s390/crypto: simplify return code handling

The CPACF instructions can complete with three different condition codes:
CC=0 for successful completion, CC=1 if the protected key verification
failed, and CC=3 for partial completion.

The inline functions will restart the CPACF instruction for partial
completion, this removes the CC=3 case. The CC=1 case is only relevant
for the protected key functions of the KM, KMC, KMAC and KMCTR
instructions. As the protected key functions are not used by the
current code, there is no need for any kind of return code handling.

Reviewed-by: Harald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>