Convert 'int i' to 'size_t i' in tests/ files

Convert the type of loop iterators named 'i', 'j', k',
'ii', 'jj', 'kk', to be 'size_t' instead of 'int' or
'unsigned int', also santizing 'ii', 'jj', 'kk' to use
the normal 'i', 'j', 'k' naming

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

tests/viratomictest.c

@@ -115,7 +115,7 @@ static void
 thread_func(void *data)
 {
     int idx = (intptr_t)data;
-    int i;
+    size_t i;
     int d;
 
     for (i = 0; i < ROUNDS; i++) {
@@ -134,7 +134,7 @@ static int
 testThreads(const void *data ATTRIBUTE_UNUSED)
 {
     int sum;
-    int i;
+    size_t i;
     virThread threads[THREADS];
 
     atomic = 0;