s390x/kvm: fix cmma reset for KVM

We must reset the CMMA states for normal memory (when not on mem path),
but the current code does the opposite. This was unnoticed for some time
as the kernel since 4.6 also had a bug which mostly disabled the paging
optimizations.

Fixes: 07059eff ("s390x/kvm: let the CPU model control CMM(A)")
Cc: qemu-stable@nongnu.org # v2.8
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>
(cherry picked from commit 0cf4d747)
Signed-off-by: NMichael Roth <mdroth@linux.vnet.ibm.com>

target-s390x/kvm.c

@@ -197,7 +197,7 @@ void kvm_s390_cmma_reset(void)
         .attr = KVM_S390_VM_MEM_CLR_CMMA,
     };
 
-    if (!mem_path || !kvm_s390_cmma_available()) {
+    if (mem_path || !kvm_s390_cmma_available()) {
         return;
     }