Clean up log output from main driver

There were a few messages being added to the log inside if statements that
should always evaluate to .false. (there will always be at least one tracer,
and currently there is guaranteed to be at least one forcing field requested
for surface_flux_compute() as well)

tests/driver_src/marbl.F90

@@ -373,9 +373,6 @@ Program marbl
       if (.not. marbl_instances(1)%StatusLog%labort_marbl) then
         ! Log tracers requested for initialization
         call driver_status_log%log_header('Requested tracers', subname)
-        ! Provide message if no tracers are requested
-        if (size(marbl_instances(1)%tracer_metadata) == 0) &
-          call driver_status_log%log_noerror('No tracers requested!', subname)
         do n=1, size(marbl_instances(1)%tracer_metadata)
           write(log_message, "(I0, 5A)") n, '. ',                                &
             trim(marbl_instances(1)%tracer_metadata(n)%short_name), ' (units: ', &
@@ -393,9 +390,6 @@ Program marbl
       if (.not. marbl_instances(1)%StatusLog%labort_marbl) then
         ! Log requested surface forcing fields
         call driver_status_log%log_header('Requested surface forcing fields', subname)
-        ! Provide message if no surface flux forcings are requested
-        if (size(marbl_instances(1)%surface_flux_forcings) == 0) &
-          call driver_status_log%log_noerror('No forcing fields requested!', subname)
         do n=1,size(marbl_instances(1)%surface_flux_forcings)
           write(log_message, "(I0, 5A)") n, '. ', &
                 trim(marbl_instances(1)%surface_flux_forcings(n)%metadata%varname), &
@@ -407,7 +401,7 @@ Program marbl
         call driver_status_log%log_header('Requested interior forcing fields', subname)
         ! Provide message if no itnerior tendency forcings are requested
         if (size(marbl_instances(1)%interior_tendency_forcings) == 0) &
-          call driver_status_log%log_noerror('No forcing fields requested!', subname)
+          call driver_status_log%log_noerror('No forcing fields requested for interior_tendency_compute()!', subname)
         do n=1,size(marbl_instances(1)%interior_tendency_forcings)
           write(log_message, "(I0, 5A)") n, '. ', &
                trim(marbl_instances(1)%interior_tendency_forcings(n)%metadata%varname), &