Fix accidental implicit cast in HR-timer conversion

Fix the hrtimer_add_expires_ns() function.  It should take a 'u64 ns' argument,
but rather takes an 'unsigned long ns' argument - which might only be 32-bits.

On FRV, this results in the kernel locking up because hrtimer_forward() passes
the result of a 64-bit multiplication to this function, for which the compiler
discards the top 32-bits - something that didn't happen when ktime_add_ns() was
called directly.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/hrtimer.h

@@ -239,7 +239,7 @@ static inline void hrtimer_add_expires(struct hrtimer *timer, ktime_t time)
 	timer->_softexpires = ktime_add_safe(timer->_softexpires, time);
 }
 
-static inline void hrtimer_add_expires_ns(struct hrtimer *timer, unsigned long ns)
+static inline void hrtimer_add_expires_ns(struct hrtimer *timer, u64 ns)
 {
 	timer->_expires = ktime_add_ns(timer->_expires, ns);
 	timer->_softexpires = ktime_add_ns(timer->_softexpires, ns);