CAM regression test is failing in lnd_set_decomp_and_domain.F90 when using ifx

### Brief summary of bug

The CAM CONUS test is failing in lnd_set_decomp_and_domain.F90 when using ifx

### General bug information
CTSM tag: Using Bill's fork; hash c7230f0

**Does this bug cause significantly incorrect results in the model's science?** [Yes / No]
yes

**Configurations affected:** [Fill this in if known.]
CAM regression test: SMS_D_Ln9_P1536x1.ne0CONUSne30x8_ne0CONUSne30x8_mt12.FCHIST.derecho_intel.cam-outfrq9s

### Details of bug

Getting `floating invalid` at line 510 of lnd_set_decomp_and_domain.F90

### Important details of your setup / configuration so we can reproduce the bug

Using cam6_4_152 with Bill's CTSM and MOSART forks with fixes for ifx. [If you'd like to use my fork with these changes you can clone https://github.com/cacraigucar/CAM; hash 60bc7b0]

### Important output or errors that show the problem

You can see my test at: /glade/derecho/scratch/cacraig/aux_cam_intel_20260219092032/SMS_D_Ln9_P1536x1.ne0CONUSne30x8_ne0CONUSne30x8_mt12.FCHIST.derecho_intel.cam-outfrq9s.GC.aux_cam_intel_20260219092032/run
NOTE: This used hash a61bea6 of my CAM fork, before a couple of CAM fixes were made in this branch.