btrfs: delete duplicated words + other fixes in comments

Delete repeated words in fs/btrfs/.
{to, the, a, and old}
and change "into 2 part" to "into 2 parts".

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 9f72b09..b1f6662 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2928,7 +2928,7 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device
 	}
 
 	/*
-	 * Verify the type first, if that or the the checksum value are
+	 * Verify the type first, if that or the checksum value are
 	 * corrupted, we'll find out
 	 */
 	csum_type = btrfs_super_csum_type(disk_super);