Blackfin: fix typo in byteswap.h commit

The Blackfin port hasn't been compiling cleanly, so this typo was missed
in the byteswap unification commit.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

libc/sysdeps/linux/bfin/bits/byteswap.h

@@ -10,7 +10,7 @@
 #ifndef _ASM_BITS_BYTESWAP_H
 #define _ASM_BITS_BYTESWAP_H 1
 
-#define __bswap_non_constant_16(x)
+#define __bswap_non_constant_16(x) \
      (__extension__							      \
       ({ register unsigned short int __v;				      \
 	 __asm__ ("%0 = PACK (%1.L, %1.L);"				      \