powerpc: Fix size of st_nlink on 64bit

commit e57f93cc (powerpc: get rid of nlink_t uses, switch to
explicitly-sized type) changed the size of st_nlink on ppc64 from
a long to a short, resulting in boot failures.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

arch/powerpc/include/asm/stat.h

@@ -30,7 +30,7 @@ struct stat {
 	unsigned long	st_dev;
 	ino_t		st_ino;
 #ifdef __powerpc64__
-	unsigned short	st_nlink;
+	unsigned long	st_nlink;
 	mode_t		st_mode;
 #else
 	mode_t		st_mode;