Reverse the order of tests for better legibility and logical sense.

Suggested by @pprindeville.

src/iperf_client_api.c

@@ -382,8 +382,8 @@ iperf_connect(struct iperf_test *test)
 	 * Regardless of whether explicitly or implicitly set, if the
 	 * block size is larger than the MSS, print a warning.
 	 */
-	if (test->settings->blksize > test->ctrl_sck_mss &&
-	    test->ctrl_sck_mss > 0) {
+	if (test->ctrl_sck_mss > 0 &&
+	    test->settings->blksize > test->ctrl_sck_mss) {
 	    char str[128];
 	    snprintf(str, sizeof(str),
 		     "UDP block size %d exceeds TCP MSS %d, may result in fragmentation / drops", test->settings->blksize, test->ctrl_sck_mss);