ext4: Fix printf() format string error

Fix the following error in the ext4 command:

cmd_ext4.c:110:3: error: format '%lu' expects argument of type
'long unsigned int', but argument 4 has type 'int' [-Werror=format]

Signed-off-by: Simon Glass <sjg@chromium.org>

common/cmd_ext4.c

@@ -101,7 +101,7 @@ int do_ext4_write(cmd_tbl_t *cmdtp, int flag, int argc,
 
 	/* mount the filesystem */
 	if (!ext4fs_mount(info.size)) {
-		printf("Bad ext4 partition %s %d:%lu\n", argv[1], dev, part);
+		printf("Bad ext4 partition %s %d:%d\n", argv[1], dev, part);
 		goto fail;
 	}