style: do not "break" in switch() after "return"

Remove this unreachable code. It was found by SunCC, it's found by a
non-fatal warning emitted by SunCC. It's one of the things it's more
vehement about than GCC & Clang.

It complains about a lot of other similarly unreachable code, e.g. a
BUG(...) without a "return", and a "return 0" after a long if/else,
both of whom have "return" statements. Those are also genuine
redundancies to a compiler, but arguably make the code a bit easier to
read & less fragile to maintain.

These return/break cases are just unnecessary however, and as seen
here the surrounding code just did a plain "return" without a "break"
already.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

apply.c

@@ -3948,10 +3948,8 @@ static int check_patch(struct apply_state *state, struct patch *patch)
 			break; /* happy */
 		case EXISTS_IN_INDEX:
 			return error(_("%s: already exists in index"), new_name);
-			break;
 		case EXISTS_IN_INDEX_AS_ITA:
 			return error(_("%s: does not match index"), new_name);
-			break;
 		case EXISTS_IN_WORKTREE:
 			return error(_("%s: already exists in working directory"),
 				     new_name);

builtin/fast-export.c

@@ -923,7 +923,6 @@ static struct commit *get_commit(struct rev_cmdline_entry *e, char *full_name)
 		if (!tag)
 			die("Tag %s points nowhere?", e->name);
 		return (struct commit *)tag;
-		break;
 	}
 	default:
 		return NULL;