Correct some sizeof(size_t) != sizeof(unsigned long) typing errors

Fix size_t vs. unsigned long pointer mismatch warnings introduced
with the addition of strbuf_detach().

Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

builtin-apply.c

@@ -152,7 +152,7 @@ struct patch {
 	unsigned int is_rename:1;
 	struct fragment *fragments;
 	char *result;
-	unsigned long resultsize;
+	size_t resultsize;
 	char old_sha1_prefix[41];
 	char new_sha1_prefix[41];
 	struct patch *next;