hrtimer: Rework hrtimer_nanosleep to make sys_compat_nanosleep easier

Pull the copy_to_user out of hrtimer_nanosleep and into the callers
(common_nsleep, sys_nanosleep) in preparation for converting
compat_sys_nanosleep to use hrtimers.

Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
index 540799b..7a9398e 100644
--- a/include/linux/hrtimer.h
+++ b/include/linux/hrtimer.h
@@ -300,7 +300,7 @@
 
 /* Precise sleep: */
 extern long hrtimer_nanosleep(struct timespec *rqtp,
-			      struct timespec __user *rmtp,
+			      struct timespec *rmtp,
 			      const enum hrtimer_mode mode,
 			      const clockid_t clockid);
 extern long hrtimer_nanosleep_restart(struct restart_block *restart_block);