rpm_suspend() simple bails out when conditions are wrong. But this is not
immediately obvious from the code.  Make it clear what we do when conditions
are wrong in rpm_suspend().
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>