[ACPI] fix acpi_os_wait_sempahore() finite timeout case (AE_TIME warning)

Before this fix, the finite timeout case
behaved like the no-timeout (trylock) case.

http://bugzilla.kernel.org/show_bug.cgi?id=4588

Signed-off-by: Luming Yu <luming.yu@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/acpi/osl.c

@@ -836,7 +836,7 @@ acpi_status acpi_os_wait_semaphore(acpi_handle handle, u32 units, u16 timeout)
 			static const int quantum_ms = 1000 / HZ;
 
 			ret = down_trylock(sem);
-			for (i = timeout; (i > 0 && ret < 0); i -= quantum_ms) {
+			for (i = timeout; (i > 0 && ret != 0); i -= quantum_ms) {
 				schedule_timeout_interruptible(1);
 				ret = down_trylock(sem);
 			}