[PATCH] sleep: Fix oops in enter_state

If ACPI sleep is not configured, but someone still wants to run swsusp,
he'd get oops in enter_state.  This is regression since 2.6.14 and this
fixes it.
Signed-off-by: NPavel Machek <pavel@suse.cz>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

kernel/power/main.c

@@ -167,7 +167,7 @@ static int enter_state(suspend_state_t state)
 {
 	int error;
 
-	if (pm_ops->valid && !pm_ops->valid(state))
+	if (pm_ops && pm_ops->valid && !pm_ops->valid(state))
 		return -ENODEV;
 	if (down_trylock(&pm_sem))
 		return -EBUSY;