btrfs: Fix misspellings in comments.

Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index cca21ff..318b048 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -62,7 +62,7 @@
 
 /**
  * free_extent_map - drop reference count of an extent_map
- * @em:		extent map beeing releasead
+ * @em:		extent map being releasead
  *
  * Drops the reference out on @em by one and free the structure
  * if the reference count hits zero.
@@ -422,7 +422,7 @@
 /**
  * remove_extent_mapping - removes an extent_map from the extent tree
  * @tree:	extent tree to remove from
- * @em:		extent map beeing removed
+ * @em:		extent map being removed
  *
  * Removes @em from @tree.  No reference counts are dropped, and no checks
  * are done to see if the range is in use