ext4: Fix misspellings using 'codespell' tool

Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index e7580ae..916e884 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3220,7 +3220,7 @@
  * ext4_split_extents() splits an extent and mark extent which is covered
  * by @map as split_flags indicates
  *
- * It may result in splitting the extent into multiple extents (upto three)
+ * It may result in splitting the extent into multiple extents (up to three)
  * There are three possibilities:
  *   a> There is no split required
  *   b> Splits in two extents: Split is happening at either end of the extent