s390/kvm: remove explicit -EFAULT return code checking on guest access

Let's change to the paradigm that every return code from guest memory
access functions that is not zero translates to -EFAULT and do not
explictly compare.
Explictly comparing the return value with -EFAULT has already shown to
be a bit fragile. In addition this is closer to the handling of
copy_to/from_user functions, which imho is in general a good idea.

Also shorten the return code handling in interrupt.c a bit.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c
index f26ff1e..9b22047 100644
--- a/arch/s390/kvm/intercept.c
+++ b/arch/s390/kvm/intercept.c
@@ -45,7 +45,7 @@
 	do {
 		rc = get_guest_u64(vcpu, useraddr,
 				   &vcpu->arch.sie_block->gcr[reg]);
-		if (rc == -EFAULT) {
+		if (rc) {
 			kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
 			break;
 		}
@@ -79,7 +79,7 @@
 	reg = reg1;
 	do {
 		rc = get_guest_u32(vcpu, useraddr, &val);
-		if (rc == -EFAULT) {
+		if (rc) {
 			kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
 			break;
 		}