Get rid of some compiler warnings about iprintf.

src/iperf_api.c

@@ -1717,11 +1717,11 @@ iperf_print_results(struct iperf_test *test)
 	    iprintf(test, "Test Complete. Summary Results:\n");
 	if (test->protocol->id == Ptcp)
 	    if (test->sender_has_retransmits)
-		iprintf(test, report_bw_retrans_header);
+		iprintf(test, "%s", report_bw_retrans_header);
 	    else
-		iprintf(test, report_bw_header);
+		iprintf(test, "%s", report_bw_header);
 	else
-	    iprintf(test, report_bw_udp_header);
+	    iprintf(test, "%s", report_bw_udp_header);
     }
 
     start_time = 0.;
@@ -1897,11 +1897,11 @@ print_interval_results(struct iperf_test *test, struct iperf_stream *sp, cJSON *
 	    */
 	    if (timeval_equals(&sp->result->start_time, &irp->interval_start_time))
 		if (test->sender && test->sender_has_retransmits)
-		    iprintf(test, report_bw_retrans_header);
+		    iprintf(test, "%s", report_bw_retrans_header);
 		else
-		    iprintf(test, report_bw_header);
+		    iprintf(test, "%s", report_bw_header);
 	    else if (test->num_streams > 1)
-		iprintf(test, report_bw_separator);
+		iprintf(test, "%s", report_bw_separator);
 	}
     }
 

src/iperf_client_api.c

@@ -341,7 +341,7 @@ iperf_run_client(struct iperf_test * test)
 	cJSON_AddItemToObject(test->json_start, "system_info", cJSON_CreateString(get_system_info()));
     } else if (test->verbose) {
 	iprintf(test, "%s\n", version);
-	iprintf(test, " ");
+	iprintf(test, "%s", "");
 	fflush(stdout);
 	system("uname -a");
     }

src/iperf_server_api.c

@@ -436,7 +436,7 @@ iperf_run_server(struct iperf_test *test)
 	cJSON_AddItemToObject(test->json_start, "system_info", cJSON_CreateString(get_system_info()));
     } else if (test->verbose) {
 	iprintf(test, "%s\n", version);
-	iprintf(test, " ");
+	iprintf(test, "%s", "");
 	fflush(stdout);
 	system("uname -a");
     }