No error or msg at all when tail input not readable

## Bug Report

**Describe the bug**

fluent-bit fails to emanate any error, warning, or message at all, if the file(s) in `tail` are not readable by the invoking user.

**To Reproduce**

Use IronBank fluent-bit Docker image and official fluent-bit helm chart. Helm chart parameter for image:

```yaml
image:
repository: registry1.dso.mil/ironbank/opensource/fluent/fluent-bit
tag: "1.9.2"
imagePullSecrets:
- name:
```

for Kubernetes daemonset:

```
sh-4.4$ grep INPUT -A 10 /fluent-bit/etc/fluent-bit.conf
[INPUT]
Name tail
Path /var/log/containers/*.log
multiline.parser docker, cri
Tag kube.*
Mem_Buf_Limit 5MB
Skip_Long_Lines On
Buffer_Chunk_Size 64KB
Buffer_Max_Size 128KB
```

**Expected behavior**

Give me any indication at all there is a problem.

**Your Environment**

* Version used: fluent-bit 1.92
* Configuration: see above and below
* Environment name and version (e.g. Kubernetes? What version?): Kubernetes 1.21
* Helm chart version 0.19.20

Full Helm config from charts/fluent-bit/values.yaml:

```yaml
fluent-bit:
env:
- name: ELASTICSEARCH_PASSWORD
valueFrom:
secretKeyRef:
name: REDACTED
key: REDACTED
# We copy/modify several of the upstream default configs to increase buffer sizes
# https://github.com/fluent/helm-charts/blob/main/charts/fluent-bit/values.yaml
config:
inputs: |
[INPUT]
Name tail
Path /var/log/containers/*.log
multiline.parser docker, cri
Tag kube.*
Mem_Buf_Limit 5MB
Skip_Long_Lines On
Buffer_Chunk_Size 64KB
Buffer_Max_Size 128KB
[INPUT]
Name systemd
Tag host.*
Systemd_Filter _SYSTEMD_UNIT=kubelet.service
Read_From_Tail On
filters: |
[FILTER]
Name kubernetes
Match kube.*
Merge_Log On
Keep_Log Off
K8S-Logging.Parser On
K8S-Logging.Exclude On
Buffer_Size 256KB
outputs: |
[OUTPUT]
Name es
Match kube.*
Host monitoring-es-http
Retry_Limit False
Index fluent-bit-kube
HTTP_User REDACTED
HTTP_Passwd ${ELASTICSEARCH_PASSWORD}
tls On
tls.verify On
tls.ca_file /usr/local/share/ca-certificates/elasticsearch.crt
Buffer_Size 128KB
net.keepalive false
Replace_Dots On
[OUTPUT]
Name es
Match host.*
Host monitoring-es-http
Retry_Limit False
Index fluent-bit-host
HTTP_User REDACTED
HTTP_Passwd ${ELASTICSEARCH_PASSWORD}
tls On
tls.verify On
tls.ca_file /usr/local/share/ca-certificates/elasticsearch.crt
Buffer_Size 128KB
net.keepalive false
Replace_Dots On
daemonSetVolumes:
- hostPath:
path: /var/log
type: ''
name: varlog
- hostPath:
path: /var/lib/docker/containers
type: ''
name: varlibdockercontainers
- hostPath:
path: /etc/machine-id
type: File
name: etcmachineid
- name: es-certs
secret:
secretName: REDACTED
items:
- key: ca.crt
path: elasticsearch.crt
daemonSetVolumeMounts:
- mountPath: /var/log
name: varlog
- mountPath: /var/lib/docker/containers
name: varlibdockercontainers
readOnly: true
- mountPath: /etc/machine-id
name: etcmachineid
readOnly: true
- name: es-certs
mountPath: /usr/local/share/ca-certificates
readOnly: true
```

Now exec into container:

```
kubectl exec -it -n redacted ds/fluent-bit-logging -- sh
```

Then:

```
sh-4.4$ id
uid=1000(fluent) gid=1000(fluent) groups=1000(fluent)
sh-4.4$ ls -ld /var/log
drwxr-xr-x 10 root root 4096 Apr 22 08:07 /var/log
sh-4.4$ ls -la /var/log | head
total 26676
drwxr-xr-x 10 root root 4096 Apr 22 08:07 .
drwxr-xr-x 1 root root 17 Nov 3 13:50 ..
-rw-r--r-- 1 root root 591 Oct 25 21:13 alternatives.log
drwxr-xr-x 3 root root 17 Oct 25 21:13 amazon
drwx------ 2 root root 42 Mar 12 21:38 audit
drwxr-xr-x 2 root root 129 Apr 4 02:29 aws-routed-eni
-rw-r--r-- 1 root root 28 Mar 19 14:16 bigfix-install.log
-rw------- 1 root root 512 Oct 25 21:13 boot.log
-rw------- 1 root utmp 0 Apr 1 07:47 btmp
sh-4.4$ pwd
/fluent-bit
```

As shown here the IronBank image uses a user of `fluent` while /var/log files are only readable by root. Sure, one fix is the correct the read permission or owner itself. However, the purpose of this issue is to show that fluent-bit doesn't produce any useful logs to point out this error. Pods are healthy and this is the only log i get:

```
2022/04/22 13:38:09] [ info] [filter:kubernetes:kubernetes.0] https=1 host=kubernetes.default.svc port=443
[2022/04/22 13:38:09] [ info] [filter:kubernetes:kubernetes.0] local POD info OK
[2022/04/22 13:38:09] [ info] [filter:kubernetes:kubernetes.0] testing connectivity with API server...
[2022/04/22 13:38:09] [ info] [filter:kubernetes:kubernetes.0] connectivity OK
[2022/04/22 13:38:09] [ info] [output:es:es.0] worker #0 started
[2022/04/22 13:38:09] [ info] [output:es:es.0] worker #1 started
[2022/04/22 13:38:09] [ info] [output:es:es.1] worker #0 started
[2022/04/22 13:38:09] [ info] [output:es:es.1] worker #1 started
[2022/04/22 13:38:09] [ info] [http_server] listen iface=0.0.0.0 tcp_port=2020
[2022/04/22 13:38:09] [ info] [sp] stream processor started
```