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/logfs/inode.c b/fs/logfs/inode.c
index adb9011..af49e2d 100644
--- a/fs/logfs/inode.c
+++ b/fs/logfs/inode.c
@@ -33,7 +33,7 @@
  * are being written out - and waiting for GC to make progress, naturally.
  *
  * So we cannot just call iget() or some variant of it, but first have to check
- * wether the inode in question might be in I_FREEING state.  Therefore we
+ * whether the inode in question might be in I_FREEING state.  Therefore we
  * maintain our own per-sb list of "almost deleted" inodes and check against
  * that list first.  Normally this should be at most 1-2 entries long.
  *