consolidate umode_t declarations

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

include/linux/types.h

@@ -24,6 +24,7 @@ typedef __kernel_fd_set		fd_set;
 typedef __kernel_dev_t		dev_t;
 typedef __kernel_ino_t		ino_t;
 typedef __kernel_mode_t		mode_t;
+typedef unsigned short		umode_t;
 typedef __kernel_nlink_t	nlink_t;
 typedef __kernel_off_t		off_t;
 typedef __kernel_pid_t		pid_t;