bury __kernel_nlink_t, make internal nlink_t consistent

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

arch/m68k/include/asm/posix_types.h

@@ -10,9 +10,6 @@
 typedef unsigned short	__kernel_mode_t;
 #define __kernel_mode_t __kernel_mode_t
 
-typedef unsigned short	__kernel_nlink_t;
-#define __kernel_nlink_t __kernel_nlink_t
-
 typedef unsigned short	__kernel_ipc_pid_t;
 #define __kernel_ipc_pid_t __kernel_ipc_pid_t