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: Pavel Machek <pavel@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
 {
        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;