ieee802154: cleanup ieee802154_le64_to_be64

This patch cleanups the ieee802154_le64_to_be64 function. This patch
removes an unnecessary temporary variable.
Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

include/net/mac802154.h

@@ -244,9 +244,7 @@ static inline void ieee802154_be64_to_le64(void *le64_dst, const void *be64_src)
  */
 static inline void ieee802154_le64_to_be64(void *be64_dst, const void *le64_src)
 {
-	__be64 tmp = (__force __be64)swab64p(le64_src);
-
-	memcpy(be64_dst, &tmp, IEEE802154_EXTENDED_ADDR_LEN);
+	__put_unaligned_memmove64(swab64p(le64_src), be64_dst);
 }
 
 /* Basic interface to register ieee802154 hwice */