Fix a crash that can be triggered by libiperf3 clients that don't use

iperf_parse_arguments().  Basically we need to initialize the
output stream in the iperf_test structure regardless of whether
iperf_parse_arguments() gets called; some programs (in particular
the programs in the examples/ directory and bwctl) don't do this
(and indeed should not need to).

This problem was introduced in the solution for Issue #119; the fix
needs to be merged to any codeline where fixes for Issue #119 go.

src/iperf_api.c

@@ -802,7 +802,7 @@ iperf_parse_arguments(struct iperf_test *test, int argc, char **argv)
         }
     }
 
-    /* Set logging to a file if specified, otherwise stdout*/
+    /* Set logging to a file if specified, otherwise use the default (stdout) */
     if (test->logfile) {
 	test->outfile = fopen(test->logfile, "a+");
 	if (test->outfile == NULL) {
@@ -810,9 +810,6 @@ iperf_parse_arguments(struct iperf_test *test, int argc, char **argv)
 	    return -1;
 	}
     }
-    else {
-	test->outfile = stdout;
-    }
 
     /* Check flag / role compatibility. */
     if (test->role == 'c' && server_flag) {
@@ -1514,6 +1511,9 @@ iperf_new_test()
     }
     memset(test->settings, 0, sizeof(struct iperf_settings));
 
+    /* By default all output goes to stdout */
+    test->outfile = stdout;
+
     return test;
 }