Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
diff --git a/fs/namei.c b/fs/namei.c
index 3cb616d..e6cd611 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -70,7 +70,7 @@
  * name indicated by the symlink. The old code always complained that the
  * name already exists, due to not following the symlink even if its target
  * is nonexistent.  The new semantics affects also mknod() and link() when
- * the name is a symlink pointing to a non-existant name.
+ * the name is a symlink pointing to a non-existent name.
  *
  * I don't know which semantics is the right one, since I have no access
  * to standards. But I found by trial that HP-UX 9.0 has the full "new"