s390/ap: fix status returned by ap_aqic()

There function ap_aqic() tries to grab the status from the
wrong part of the register. Thus we always end up with
zeros. Which is wrong, among others, because we detect
failures via status.response_code.

Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Reported-by: Janosch Frank <frankja@linux.ibm.com>
Fixes: 159491f3 ("s390/ap: rework assembler functions to use unions for in/out register variables")
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>