Merge pull request #3078 from jedwards4b/shr_pio_bug_fix

When using pio2 if the pio_numiotasks and pio_stride indicate processors above the model task count you will get an error. This change prevents that happening.

Test suite: by hand SMS_P45.f19_g16.X
Test baseline:
Test namelist changes:
Test status: bit for bit
Fixes

User interface changes?:

Update gh-pages html (Y/N)?:

Code review:

share/util/shr_pio_mod.F90

@@ -693,6 +693,7 @@ subroutine shr_pio_namelist_set(npes,mycomm, pio_stride, pio_root, pio_numiotask
          (pio_iotype .eq. PIO_IOTYPE_PNETCDF .or. &
          pio_iotype .eq. PIO_IOTYPE_NETCDF4P)) then
        pio_numiotasks = 2
+       pio_stride = min(pio_stride, npes/2)
     endif
 
     !--------------------------------------------------------------------------