target-arm: fix sorting issue of KVM cpreg list

The compare_u64 function was not sorting the KVM cpreg_list in the
right way due to the wrong returned value.  Since we are comparing
two 64bit values we can't simply return their difference if the
returned type is int.

Signed-off-by: Alvise Rigo <a.rigo@virtualopensystems.com>
Message-id: 1381513125-26802-2-git-send-email-a.rigo@virtualopensystems.com
[PMM: fixed coding style, indent and commit message formatting]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

target-arm/kvm.c

diff --git a/target-arm/kvm.c b/target-arm/kvm.c
index b92e00d..6e5cd36 100644
--- a/target-arm/kvm.c
+++ b/target-arm/kvm.c
@@ -67,7 +67,13 @@
 
 static int compare_u64(const void *a, const void *b)
 {
-    return *(uint64_t *)a - *(uint64_t *)b;
+    if (*(uint64_t *)a > *(uint64_t *)b) {
+        return 1;
+    }
+    if (*(uint64_t *)a < *(uint64_t *)b) {
+        return -1;
+    }
+    return 0;
 }
 
 int kvm_arch_init_vcpu(CPUState *cs)