Fix missing newline at end of shell_commands file

Author: singhbalwinder

components/eamxx/cime_config/testdefs/testmods_dirs/eamxx/mam4xx/constituent_fluxes/shell_commands

@@ -6,4 +6,4 @@ ATMCHANGE physics::atm_procs_list="mam4_constituent_fluxes,mac_aero_mic,rrtmgp"
 #------------------------------------------------------
 # Set rest of the options to default
 #------------------------------------------------------
-$CIMEROOT/../components/eamxx/cime_config/testdefs/testmods_dirs/eamxx/mam4xx/set_default_eamxx_options
+$CIMEROOT/../components/eamxx/cime_config/testdefs/testmods_dirs/eamxx/mam4xx/set_default_eamxx_options