s390/vfio-ap: no need to check the 'E' and 'I' bits in APQSW after TAPQ

s390/vfio-ap: no need to check the 'E' and 'I' bits in APQSW after TAPQ

After a ZAPQ is executed to reset a queue, if the queue is not empty or
interrupts are still enabled, the vfio_ap driver will wait for the reset
operation to complete by repeatedly executing the TAPQ instruction and
checking the 'E' and 'I' bits in the APQSW to verify that the queue is
empty and interrupts are disabled. This is unnecessary because it is
sufficient to check only the response code in the APQSW. If the reset is
still in progress, the response code will be 02; however, if the reset has
completed successfully, the response code will be 00.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Acked-by: Janosch Frank <frankja@linux.ibm.com>
Tested-by: Viktor Mihajlovski <mihajlov@linux.ibm.com>
Link: https://lore.kernel.org/r/20230815184333.6554-2-akrowiak@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>