coccinelle: make use of the "type" FREE_AND_NULL() rule

Apply the result of the just-added coccinelle rule. This manually
excludes a few occurrences, mostly things that resulted in many
FREE_AND_NULL() on one line, that'll be manually fixed in a subsequent
change.

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

builtin/unpack-objects.c

@@ -112,8 +112,7 @@ static void *get_data(unsigned long size)
 			break;
 		if (ret != Z_OK) {
 			error("inflate returned %d", ret);
-			free(buf);
-			buf = NULL;
+			FREE_AND_NULL(buf);
 			if (!recover)
 				exit(1);
 			has_errors = 1;