Remove one to many n's in a word

Signed-off-by: Justin P. Mattock <justinmattock@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index fdce879..7b658d2 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2489,7 +2489,7 @@
 	 * ERROR state on disk.
 	 *
 	 * 2. when btrfs flips readonly just in btrfs_commit_super,
-	 * and in such case, btrfs cannnot write sb via btrfs_commit_super,
+	 * and in such case, btrfs cannot write sb via btrfs_commit_super,
 	 * and since fs_state has been set BTRFS_SUPER_FLAG_ERROR flag,
 	 * btrfs will cleanup all FS resources first and write sb then.
 	 */