Skip test/move_pages if we don't have at least two nodes available

If hardware that doesn't support this test is not available, we should
SKIP rather than FAIL.

This is akin to what we've done with `test/regress` in commit 4042d9e.

Signed-off-by: Filipe Brandenburger <filbranden@gmail.com>

test/move_pages.c

@@ -50,7 +50,7 @@ int main(int argc, char **argv)
 
 	if (nr_nodes < 2) {
 		printf("A minimum of 2 nodes is required for this test.\n");
-		exit(1);
+		exit(77);
 	}
 	if (nr_nodes == -1) {
 		printf("Mismatch between congfigured nodes and memory-rich nodes.\n");