test_fvm_mapping.F90 is ignored in cesm build

This issue is for your information only - the fix will be made in the FMS library so
no action is needed on your part.

The issue is that the FMS library build requires that you ignore files which begin with "test_" to do this we have an environment variable that is set during the FMS build, mkSrcfiles_skip_prefix,that tells mkSrcFiles to ignore files that begin with test_.   Cam se dycore has a new file test_fvm_mapping.F90 which is not being compiled because the environment variable set by the FMS build is not unset when it completes.  I'll have a new FMS tag shortly to correct this problem. This will affect BMOM cases using the se dycore.