Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c
index 96804a1..f55ae23b 100644
--- a/fs/autofs4/root.c
+++ b/fs/autofs4/root.c
@@ -612,7 +612,7 @@
  * set the DMANAGED_AUTOMOUNT and DMANAGED_TRANSIT flags on the leaves
  * of the directory tree. There is no need to clear the automount flag
  * following a mount or restore it after an expire because these mounts
- * are always covered. However, it is neccessary to ensure that these
+ * are always covered. However, it is necessary to ensure that these
  * flags are clear on non-empty directories to avoid unnecessary calls
  * during path walks.
  */