radix tree test suite: Dial down verbosity with -v

Make the output of radix tree test suite less verbose by default and add
-v and -vv command line options for increasing level of verbosity.

Signed-off-by: Rehas Sachdeva <aquannie@gmail.com>
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
diff --git a/tools/testing/radix-tree/iteration_check.c b/tools/testing/radix-tree/iteration_check.c
index 7572b7e..a92bab5 100644
--- a/tools/testing/radix-tree/iteration_check.c
+++ b/tools/testing/radix-tree/iteration_check.c
@@ -177,7 +177,7 @@ void iteration_test(unsigned order, unsigned test_duration)
 {
 	int i;
 
-	printf("Running %siteration tests for %d seconds\n",
+	printv(1, "Running %siteration tests for %d seconds\n",
 			order > 0 ? "multiorder " : "", test_duration);
 
 	max_order = order;