efi.h: use %pUl to print UUIDs

Shrinks vmlinux

without:
$ size vmlinux
   text    data     bss     dec     hex filename
6975863  679652 1359668 9015183  898f8f vmlinux

with:
$ size vmlinux
   text    data     bss     dec     hex filename
6975639 679652 1359668 9014959 898eaf vmlinux
Signed-off-by: NJoe Perches <joe@perches.com>
Cc: Jeff Garzik <jgarzik@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

include/linux/efi.h

@@ -280,11 +280,7 @@ efi_guidcmp (efi_guid_t left, efi_guid_t right)
 static inline char *
 efi_guid_unparse(efi_guid_t *guid, char *out)
 {
-	sprintf(out, "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
-		guid->b[3], guid->b[2], guid->b[1], guid->b[0],
-		guid->b[5], guid->b[4], guid->b[7], guid->b[6],
-		guid->b[8], guid->b[9], guid->b[10], guid->b[11],
-		guid->b[12], guid->b[13], guid->b[14], guid->b[15]);
+	sprintf(out, "%pUl", guid->b);
         return out;
 }