util/stats64: Fix min/max comparisons

stat64_min_slow() and stat64_max_slow() compare the wrong way.  This
makes iotest 136 fail with clang and -m32.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20171114232223.25207-1-mreitz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 26a5db3)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

util/stats64.c

@@ -91,7 +91,7 @@ bool stat64_min_slow(Stat64 *s, uint64_t value)
     low = atomic_read(&s->low);
 
     orig = ((uint64_t)high << 32) | low;
-    if (orig < value) {
+    if (value < orig) {
         /* We have to set low before high, just like stat64_min reads
          * high before low.  The value may become higher temporarily, but
          * stat64_get does not notice (it takes the lock) and the only ill
@@ -120,7 +120,7 @@ bool stat64_max_slow(Stat64 *s, uint64_t value)
     low = atomic_read(&s->low);
 
     orig = ((uint64_t)high << 32) | low;
-    if (orig > value) {
+    if (value > orig) {
         /* We have to set low before high, just like stat64_max reads
          * high before low.  The value may become lower temporarily, but
          * stat64_get does not notice (it takes the lock) and the only ill