wl1271: remove deprecated __attribute__ ((packed))

One __attribute__ ((packed)) has been accidentally introduced in commit
be86cbea.  This patch changes it to __packed.
Signed-off-by: Luciano Coelho <luciano.coelho@nokia.com>

drivers/net/wireless/wl12xx/wl1271_cmd.h

@@ -454,6 +454,6 @@ struct wl1271_cmd_set_sta_state {
 
 	u8 state;
 	u8 padding[3];
-} __attribute__ ((packed));
+} __packed;
 
 #endif /* __WL1271_CMD_H__ */