dir: make the DO_MATCH_SUBMODULE code reusable for a non-submodule case

The specific checks done in match_pathspec_item for the DO_MATCH_SUBMODULE
case are useful for other cases which have nothing to do with submodules.
Rename this constant; a subsequent commit will make use of this change.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

dir.c

@@ -273,7 +273,7 @@ static int do_read_blob(const struct object_id *oid, struct oid_stat *oid_stat,
 
 #define DO_MATCH_EXCLUDE   (1<<0)
 #define DO_MATCH_DIRECTORY (1<<1)
-#define DO_MATCH_SUBMODULE (1<<2)
+#define DO_MATCH_LEADING_PATHSPEC (1<<2)
 
 /*
  * Does 'match' match the given name?
@@ -354,7 +354,7 @@ static int match_pathspec_item(const struct index_state *istate,
 		return MATCHED_FNMATCH;
 
 	/* Perform checks to see if "name" is a super set of the pathspec */
-	if (flags & DO_MATCH_SUBMODULE) {
+	if (flags & DO_MATCH_LEADING_PATHSPEC) {
 		/* name is a literal prefix of the pathspec */
 		int offset = name[namelen-1] == '/' ? 1 : 0;
 		if ((namelen < matchlen) &&
@@ -498,7 +498,7 @@ int submodule_path_match(const struct index_state *istate,
 					strlen(submodule_name),
 					0, seen,
 					DO_MATCH_DIRECTORY |
-					DO_MATCH_SUBMODULE);
+					DO_MATCH_LEADING_PATHSPEC);
 	return matched;
 }