[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/cifsencrypt.c b/fs/cifs/cifsencrypt.c
index 1959c7c..fe2bb7c 100644
--- a/fs/cifs/cifsencrypt.c
+++ b/fs/cifs/cifsencrypt.c
@@ -149,7 +149,7 @@
 	char temp_hash[16];
 	struct HMACMD5Context ctx;
 	char * ucase_buf;
-	wchar_t * unicode_buf;
+	__le16 * unicode_buf;
 	unsigned int i,user_name_len,dom_name_len;
 
 	if(ses == NULL)