Units of bpch ALD2_OCEAN_SOURCE diagnostic should be kgC/m2/s

The ALD2_OCEAN_SOURCE manual diagnostic (for bpch output) is defined
with units of kg/m2/s but should be kgC/m2/s.  This is necessary to
be consistent with diag3.F.

NOTE: We are phasing out bpch output soon.

Signed-off-by: Bob Yantosca <yantosca@seas.harvard.edu>

GeosCore/hcoi_gc_diagn_mod.F90

@@ -4512,7 +4512,7 @@ SUBROUTINE Diagn_Biogenic( am_I_Root, Input_Opt, HcoState, ExtState, RC )
                              HcoID     = HcoID,             &
                              SpaceDim  = 2,                 &
                              LevIDx    = -1,                &
-                             OutUnit   = 'kg/m2/s',   &
+                             OutUnit   = 'kgC/m2/s',   &
                              COL       = HcoState%Diagn%HcoDiagnIDManual,  &
                              AutoFill  = 1,                 &
                              RC        = RC                  )