[CIFS] Cleanup sparse warnings for unicode little endian casts

Following Shaggy's suggestion, do a better job on the unicode string
handling routines in cifs in specifying that the wchar_t are really
little endian widechars (__le16).

Signed-off-by: Steve French <sfrench@us.ibm.com>
diff --git a/fs/cifs/readdir.c b/fs/cifs/readdir.c
index fc61567..9b7e0ff 100644
--- a/fs/cifs/readdir.c
+++ b/fs/cifs/readdir.c
@@ -705,7 +705,7 @@
 					(__le16 *)filename, len/2, nlt);
 		else
 			pqst->len = cifs_strfromUCS_le((char *)pqst->name,
-					(wchar_t *)filename,len/2,nlt);
+					(__le16 *)filename,len/2,nlt);
 	} else {
 		pqst->name = filename;
 		pqst->len = len;