submodule: rename helper functions to avoid ambiguity

The helper functions: show_submodule_summary(),
prepare_submodule_summary() and print_submodule_summary() are used by
the builtin_diff() function in diff.c to generate a summary of
submodules in the context of a diff. Functions with similar names are to
be introduced in the upcoming port of submodule's summary subcommand.

So, rename the helper functions to '*_diff_submodule_summary()' to avoid
ambiguity.

Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Kaartic Sivaraam <kaartic.sivaraam@gmail.com>
Signed-off-by: Shourya Shukla <shouryashukla.oo@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff.c

@@ -3429,7 +3429,7 @@ static void builtin_diff(const char *name_a,
 	if (o->submodule_format == DIFF_SUBMODULE_LOG &&
 	    (!one->mode || S_ISGITLINK(one->mode)) &&
 	    (!two->mode || S_ISGITLINK(two->mode))) {
-		show_submodule_summary(o, one->path ? one->path : two->path,
+		show_submodule_diff_summary(o, one->path ? one->path : two->path,
 				&one->oid, &two->oid,
 				two->dirty_submodule);
 		return;

submodule.c

@@ -438,7 +438,7 @@ void handle_ignore_submodules_arg(struct diff_options *diffopt,
 	 */
 }
 
-static int prepare_submodule_summary(struct rev_info *rev, const char *path,
+static int prepare_submodule_diff_summary(struct rev_info *rev, const char *path,
 		struct commit *left, struct commit *right,
 		struct commit_list *merge_bases)
 {
@@ -459,7 +459,7 @@ static int prepare_submodule_summary(struct rev_info *rev, const char *path,
 	return prepare_revision_walk(rev);
 }
 
-static void print_submodule_summary(struct repository *r, struct rev_info *rev, struct diff_options *o)
+static void print_submodule_diff_summary(struct repository *r, struct rev_info *rev, struct diff_options *o)
 {
 	static const char format[] = "  %m %s";
 	struct strbuf sb = STRBUF_INIT;
@@ -610,7 +610,7 @@ output_header:
 	strbuf_release(&sb);
 }
 
-void show_submodule_summary(struct diff_options *o, const char *path,
+void show_submodule_diff_summary(struct diff_options *o, const char *path,
 		struct object_id *one, struct object_id *two,
 		unsigned dirty_submodule)
 {
@@ -632,12 +632,12 @@ void show_submodule_summary(struct diff_options *o, const char *path,
 		goto out;
 
 	/* Treat revision walker failure the same as missing commits */
-	if (prepare_submodule_summary(&rev, path, left, right, merge_bases)) {
+	if (prepare_submodule_diff_summary(&rev, path, left, right, merge_bases)) {
 		diff_emit_submodule_error(o, "(revision walker failed)\n");
 		goto out;
 	}
 
-	print_submodule_summary(sub, &rev, o);
+	print_submodule_diff_summary(sub, &rev, o);
 
 out:
 	if (merge_bases)

submodule.h

@@ -69,7 +69,7 @@ int parse_submodule_update_strategy(const char *value,
 				    struct submodule_update_strategy *dst);
 const char *submodule_strategy_to_string(const struct submodule_update_strategy *s);
 void handle_ignore_submodules_arg(struct diff_options *, const char *);
-void show_submodule_summary(struct diff_options *o, const char *path,
+void show_submodule_diff_summary(struct diff_options *o, const char *path,
 			    struct object_id *one, struct object_id *two,
 			    unsigned dirty_submodule);
 void show_submodule_inline_diff(struct diff_options *o, const char *path,