block: Remove annoying "unknown partition table" message

As Christoph put it:
  Can we just get rid of the warnings?  It's fairly annoying as devices
  without partitions are perfectly fine and very useful.

Me too I see this message every VM boot for ages on all my
devices. Would love to just remove it. For me a partition-table
is only needed for a booting BIOS, grub, and stuff.

CC: Christoph Hellwig <hch@infradead.org>
Signed-off-by: NBoaz Harrosh <boaz@plexistor.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

block/partitions/check.c

@@ -184,12 +184,12 @@ check_partition(struct gendisk *hd, struct block_device *bdev)
 	if (err)
 	/* The partition is unrecognized. So report I/O errors if there were any */
 		res = err;
-	if (!res)
-		strlcat(state->pp_buf, " unknown partition table\n", PAGE_SIZE);
-	else if (warn_no_part)
-		strlcat(state->pp_buf, " unable to read partition table\n", PAGE_SIZE);
-
-	printk(KERN_INFO "%s", state->pp_buf);
+	if (res) {
+		if (warn_no_part)
+			strlcat(state->pp_buf,
+				" unable to read partition table\n", PAGE_SIZE);
+		printk(KERN_INFO "%s", state->pp_buf);
+	}
 
 	free_page((unsigned long)state->pp_buf);
 	free_partitions(state);