[docs] Don’t use GTK-Doc syntax for internal functions

We don’t generate docs for them, reduces the number of warnings.

src/hb-subset-cff-common.cc

@@ -38,13 +38,12 @@
 
 using namespace CFF;
 
-/**
- * hb_plan_subset_cff_fdselect
- * Determine an optimal FDSelect format according to a provided plan.
+
+/* Determine an optimal FDSelect format according to a provided plan.
  *
  * Return value: FDSelect format, size, and ranges for the most compact subset FDSelect
  * along with a font index remapping table
- **/
+ */
 
 bool
 hb_plan_subset_cff_fdselect (const hb_subset_plan_t *plan,
@@ -169,10 +168,7 @@ serialize_fdselect_3_4 (hb_serialize_context_t *c,
   return_trace (true);
 }
 
-/**
- * hb_serialize_cff_fdselect
- * Serialize a subset FDSelect format planned above.
- **/
+/* Serialize a subset FDSelect format planned above. */
 bool
 hb_serialize_cff_fdselect (hb_serialize_context_t *c,
 			   const unsigned int num_glyphs,

src/hb-subset-cff1.cc

@@ -917,12 +917,6 @@ _hb_subset_cff1 (const OT::cff1::accelerator_subset_t  &acc,
   return _serialize_cff1 (c->serializer, cff_plan, acc, c->plan->num_output_glyphs ());
 }
 
-/**
- * hb_subset_cff1:
- * Subsets the CFF table according to a provided plan.
- *
- * Return value: subsetted cff table.
- **/
 bool
 hb_subset_cff1 (hb_subset_context_t *c)
 {

src/hb-subset-cff2.cc

@@ -470,10 +470,6 @@ _hb_subset_cff2 (const OT::cff2::accelerator_subset_t  &acc,
   return _serialize_cff2 (c->serializer, cff2_plan, acc, c->plan->num_output_glyphs ());
 }
 
-/**
- * hb_subset_cff2:
- * Subsets the CFF2 table according to a provided subset context.
- **/
 bool
 hb_subset_cff2 (hb_subset_context_t *c)
 {