kvm_s390_inject_program_int() and friends may fail if no memory is available.
This must be reported to the calling functions, so that this gets passed
down to user space which should fix the situation.
Alternatively we end up with guest state corruption.

So fix this and enforce return value checking by adding a __must_check
annotation to all of these function prototypes.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>