[PADLOCK] Fix sparse warning about 1-bit signed bit-field

Change the bit-field in struct cword to unsigned to shut sparse up.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/drivers/crypto/padlock.h b/drivers/crypto/padlock.h
index 3cf2b7a..b78489b 100644
--- a/drivers/crypto/padlock.h
+++ b/drivers/crypto/padlock.h
@@ -17,7 +17,7 @@
 
 /* Control word. */
 struct cword {
-	int __attribute__ ((__packed__))
+	unsigned int __attribute__ ((__packed__))
 		rounds:4,
 		algo:3,
 		keygen:1,