block/ioctl.c and fs/partition/check.c: check value returned by add_partition()

Now that add_partition() has been aught to propagate errors, let's check them.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Abdel Benamrouche <draconux@gmail.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/block/ioctl.c b/block/ioctl.c
index 52d6385..77185e5 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -17,6 +17,7 @@
 	long long start, length;
 	int part;
 	int i;
+	int err;
 
 	if (!capable(CAP_SYS_ADMIN))
 		return -EACCES;
@@ -61,9 +62,9 @@
 				}
 			}
 			/* all seems OK */
-			add_partition(disk, part, start, length, ADDPART_FLAG_NONE);
+			err = add_partition(disk, part, start, length, ADDPART_FLAG_NONE);
 			mutex_unlock(&bdev->bd_mutex);
-			return 0;
+			return err;
 		case BLKPG_DEL_PARTITION:
 			if (!disk->part[part-1])
 				return -ENXIO;