UBIFS: fix output format of INUM_WATERMARK

The INUM_WATERMARK is a unsigned 32bit value, `%d' prints it as negatave:
[ 103.682255] UBIFS warning (ubi0:0 pid 691): ubifs_new_inode: running out of inode numbers (current 122763, max -256)

Fix it as:
[ 154.422940] UBIFS warning (ubi0:0 pid 688): ubifs_new_inode: running out of inode numbers (current 122765, max 4294967040)

Signed-off-by: Sheng Yong <[e-mail]>
Signed-off-by: Artem Bityutskiy <[e-mail]>

fs/ubifs/dir.c

···
 			iput(inode);
 			return ERR_PTR(-EINVAL);
 		}
-		ubifs_warn(c, "running out of inode numbers (current %lu, max %d)",
+		ubifs_warn(c, "running out of inode numbers (current %lu, max %u)",
 			   (unsigned long)c->highest_inum, INUM_WATERMARK);
 	}