sequencer: rename reset_for_rollback to reset_merge

We are on a path to teach cherry-pick/revert how to skip commits. To
achieve this, we could really make use of existing functions.
reset_for_rollback is one such function, but the name does not
intuitively suggest to use it to reset a merge, which it was born to
perform, see 539047c ("revert: introduce --abort to cancel a failed
cherry-pick", 2011-11-23). Change the name to reset_merge to make
it more intuitive.

Signed-off-by: Rohit Ashiwal <rohit.ashiwal265@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

sequencer.c

@@ -2732,7 +2732,7 @@ static int rollback_is_safe(void)
 	return oideq(&actual_head, &expected_head);
 }
 
-static int reset_for_rollback(const struct object_id *oid)
+static int reset_merge(const struct object_id *oid)
 {
 	const char *argv[4];	/* reset --merge <arg> + NULL */
 
@@ -2754,7 +2754,7 @@ static int rollback_single_pick(struct repository *r)
 		return error(_("cannot resolve HEAD"));
 	if (is_null_oid(&head_oid))
 		return error(_("cannot abort from a branch yet to be born"));
-	return reset_for_rollback(&head_oid);
+	return reset_merge(&head_oid);
 }
 
 int sequencer_rollback(struct repository *r, struct replay_opts *opts)
@@ -2797,7 +2797,7 @@ int sequencer_rollback(struct repository *r, struct replay_opts *opts)
 		warning(_("You seem to have moved HEAD. "
 			  "Not rewinding, check your HEAD!"));
 	} else
-	if (reset_for_rollback(&oid))
+	if (reset_merge(&oid))
 		goto fail;
 	strbuf_release(&buf);
 	return sequencer_remove_state(opts);