Fix misspellings of "whether" in comments.

"Whether" is misspelled in various comments across the tree; this
fixes them. No code changes.

Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/fs/jbd/transaction.c b/fs/jbd/transaction.c
index 78b7f84..8b472c8 100644
--- a/fs/jbd/transaction.c
+++ b/fs/jbd/transaction.c
@@ -1259,7 +1259,7 @@
 		goto not_jbd;
 	}
 
-	/* keep track of wether or not this transaction modified us */
+	/* keep track of whether or not this transaction modified us */
 	was_modified = jh->b_modified;
 
 	/*