parse-option: rename parse_opt_with_commit()

Rename parse_opt_with_commit() to parse_opt_commits() to show
that it can be used to obtain a list of commits and is not
constricted to usage of '--contains' option.

Mentored-by: Christian Couder <christian.couder@gmail.com>
Mentored-by: Matthieu Moy <matthieu.moy@grenoble-inp.fr>
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/parse-options-cb.c b/parse-options-cb.c
index de75411..632f10f 100644
--- a/parse-options-cb.c
+++ b/parse-options-cb.c
@@ -77,7 +77,7 @@
 	return 0;
 }
 
-int parse_opt_with_commit(const struct option *opt, const char *arg, int unset)
+int parse_opt_commits(const struct option *opt, const char *arg, int unset)
 {
 	unsigned char sha1[20];
 	struct commit *commit;