header: fix broken headers for user space

__packed is only defined in kernel space, so we should use
__attribute__((packed)) for the code shared between kernel and user space.

Two __attribute() annotations are replaced with __attribute__() too.

Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/rfkill.h b/include/linux/rfkill.h
index 4f82326..08c32e4 100644
--- a/include/linux/rfkill.h
+++ b/include/linux/rfkill.h
@@ -81,7 +81,7 @@
 	__u8  type;
 	__u8  op;
 	__u8  soft, hard;
-} __packed;
+} __attribute__((packed));
 
 /*
  * We are planning to be backward and forward compatible with changes