[BUG] quota.get_mode fails when quota is on

Description
quota.get_mode fails when quota is on.

Setup
Create a filesystem, e.g. EXT4, and mount it.

Steps to Reproduce the behavior

root@omv5box:/home/vagrant# cat /etc/os-release 
PRETTY_NAME="Debian GNU/Linux 10 (buster)"
NAME="Debian GNU/Linux"
VERSION_ID="10"
VERSION="10 (buster)"
VERSION_CODENAME=buster
ID=debian
HOME_URL="https://www.debian.org/"
SUPPORT_URL="https://www.debian.org/support"
BUG_REPORT_URL="https://bugs.debian.org/"

root@omv5box:/home/vagrant# blkid /dev/sda1
/dev/sda1: UUID="4302e6b9-ae66-4782-a716-79cf6ee42a3a" TYPE="ext4" PARTUUID="890c42ed-3606-4fdd-b120-05a5e59a3419"

root@omv5box:/home/vagrant# mount | grep /dev/sda1
/dev/sda1 on /srv/dev-disk-by-id-scsi-0QEMU_QEMU_HARDDISK_drive-scsi0-0-1-part1 type ext4 (rw,relatime,jqfmt=vfsv0,usrjquota=aquota.user,grpjquota=aquota.group)

root@omv5box:/home/vagrant# ls -alh /srv/dev-disk-by-id-scsi-0QEMU_QEMU_HARDDISK_drive-scsi0-0-1-part1
total 52K
drwxr-xr-x  5 root root  4.0K Oct 20 15:17 .
drwxr-xr-x  8 root root  4.0K Oct 21 19:00 ..
-rw-------  1 root root  6.0K Oct 21 19:17 aquota.group
-rw-------  1 root root  7.0K Oct 21 19:17 aquota.user

root@omv5box:/home/vagrant# quotaoff /dev/sda1

root@omv5box:/home/vagrant# quotaon -p /dev/sda1
group quota on /srv/dev-disk-by-id-scsi-0QEMU_QEMU_HARDDISK_drive-scsi0-0-1-part1 (/dev/sda1) is off
user quota on /srv/dev-disk-by-id-scsi-0QEMU_QEMU_HARDDISK_drive-scsi0-0-1-part1 (/dev/sda1) is off
project quota on /srv/dev-disk-by-id-scsi-0QEMU_QEMU_HARDDISK_drive-scsi0-0-1-part1 (/dev/sda1) is off
root@omv5box:/home/vagrant# echo $?
0

root@omv5box:/home/vagrant# salt-call quota.get_mode /dev/sda1
local:
    ----------
    /srv/dev-disk-by-id-scsi-0QEMU_QEMU_HARDDISK_drive-scsi0-0-1-part1:
        ----------
        device:
            /dev/sda1
        group:
            off
        project:
            off
        user:
            off

root@omv5box:/home/vagrant# quotaon /dev/sda1
root@omv5box:/home/vagrant# quotaon -p /dev/sda1
group quota on /srv/dev-disk-by-id-scsi-0QEMU_QEMU_HARDDISK_drive-scsi0-0-1-part1 (/dev/sda1) is on
user quota on /srv/dev-disk-by-id-scsi-0QEMU_QEMU_HARDDISK_drive-scsi0-0-1-part1 (/dev/sda1) is on
project quota on /srv/dev-disk-by-id-scsi-0QEMU_QEMU_HARDDISK_drive-scsi0-0-1-part1 (/dev/sda1) is off
root@omv5box:/home/vagrant# echo $?
2

root@omv5box:/home/vagrant# salt-call quota.get_mode /dev/sda1
[ERROR   ] Command '['quotaon', '-p', '/dev/sda1']' failed with return code: 2
[ERROR   ] stdout: group quota on /srv/dev-disk-by-id-scsi-0QEMU_QEMU_HARDDISK_drive-scsi0-0-1-part1 (/dev/sda1) is on
user quota on /srv/dev-disk-by-id-scsi-0QEMU_QEMU_HARDDISK_drive-scsi0-0-1-part1 (/dev/sda1) is on
project quota on /srv/dev-disk-by-id-scsi-0QEMU_QEMU_HARDDISK_drive-scsi0-0-1-part1 (/dev/sda1) is off
[ERROR   ] retcode: 2
[ERROR   ] Command 'quotaon -p /dev/sda1' failed with return code: 2
[ERROR   ] output: group quota on /srv/dev-disk-by-id-scsi-0QEMU_QEMU_HARDDISK_drive-scsi0-0-1-part1 (/dev/sda1) is on
user quota on /srv/dev-disk-by-id-scsi-0QEMU_QEMU_HARDDISK_drive-scsi0-0-1-part1 (/dev/sda1) is on
project quota on /srv/dev-disk-by-id-scsi-0QEMU_QEMU_HARDDISK_drive-scsi0-0-1-part1 (/dev/sda1) is off
local:
    ----------
    /srv/dev-disk-by-id-scsi-0QEMU_QEMU_HARDDISK_drive-scsi0-0-1-part1:
        ----------
        device:
            /dev/sda1
        group:
            on
        project:
            off
        user:
            on

Expected behavior
The return code 2 from quotaon -p /dev/xxx should be handled properly.

Versions Report

Salt Version:
           Salt: 3001.1
 
Dependency Versions:
           cffi: Not Installed
       cherrypy: Not Installed
       dateutil: 2.7.3
      docker-py: Not Installed
          gitdb: Not Installed
      gitpython: Not Installed
         Jinja2: 2.10
        libgit2: Not Installed
       M2Crypto: Not Installed
           Mako: Not Installed
   msgpack-pure: Not Installed
 msgpack-python: 0.5.6
   mysql-python: Not Installed
      pycparser: Not Installed
       pycrypto: Not Installed
   pycryptodome: 3.6.1
         pygit2: Not Installed
         Python: 3.7.3 (default, Jul 25 2020, 13:03:44)
   python-gnupg: Not Installed
         PyYAML: 3.13
          PyZMQ: 17.1.2
          smmap: Not Installed
        timelib: Not Installed
        Tornado: 4.5.3
            ZMQ: 4.3.1
 
System Versions:
           dist: debian 10 buster
         locale: UTF-8
        machine: x86_64
        release: 4.19.0-11-amd64
         system: Linux
        version: Debian GNU/Linux 10 buster

Start at the quota.get_mode entry point and reproduce the behavior with quotaon -p on a filesystem where user and group quotas are on but project quota is off. Done means return code 2 is handled without treating the command as an unhandled failure, while the reported group, user, and project states remain available.