PM / QoS: Use the correct variable to check the QoS request type

Use the actual function argument for the validation of the request type,
instead of the type field in a fresh (supposedly zero-initialized)
request structure.

Signed-off-by: Jan H. Schönherr <jschoenh@amazon.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>