Make opt_parse_with_commit() non-static

Moving opt_parse_with_commit() from branch to a common location, in
preparation for using it in tag. Rename it to match naming convention
of other option parsing functions.

Signed-off-by: Jake Goulding <goulding@vivisimo.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/builtin-branch.c b/builtin-branch.c
index 02fa38f..82d6fb2 100644
--- a/builtin-branch.c
+++ b/builtin-branch.c
@@ -466,22 +466,6 @@
 	strbuf_release(&newsection);
 }
 
-static int opt_parse_with_commit(const struct option *opt, const char *arg, int unset)
-{
-	unsigned char sha1[20];
-	struct commit *commit;
-
-	if (!arg)
-		return -1;
-	if (get_sha1(arg, sha1))
-		die("malformed object name %s", arg);
-	commit = lookup_commit_reference(sha1);
-	if (!commit)
-		die("no such commit %s", arg);
-	commit_list_insert(commit, opt->value);
-	return 0;
-}
-
 static int opt_parse_merge_filter(const struct option *opt, const char *arg, int unset)
 {
 	merge_filter = ((opt->long_name[0] == 'n')
@@ -517,13 +501,13 @@
 			OPTION_CALLBACK, 0, "contains", &with_commit, "commit",
 			"print only branches that contain the commit",
 			PARSE_OPT_LASTARG_DEFAULT,
-			opt_parse_with_commit, (intptr_t)"HEAD",
+			parse_opt_with_commit, (intptr_t)"HEAD",
 		},
 		{
 			OPTION_CALLBACK, 0, "with", &with_commit, "commit",
 			"print only branches that contain the commit",
 			PARSE_OPT_HIDDEN | PARSE_OPT_LASTARG_DEFAULT,
-			opt_parse_with_commit, (intptr_t) "HEAD",
+			parse_opt_with_commit, (intptr_t) "HEAD",
 		},
 		OPT__ABBREV(&abbrev),