make --help return exitcode 0. Closes 5612

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/libbb/appletlib.c b/libbb/appletlib.c
index 67df446..c22686e 100644
--- a/libbb/appletlib.c
+++ b/libbb/appletlib.c
@@ -750,7 +750,7 @@
 //TODO: just compare applet_no with APPLET_NO_test
 		if (!ENABLE_TEST || strcmp(applet_name, "test") != 0) {
 			/* If you want "foo --help" to return 0: */
-			/*xfunc_error_retval = 0;*/
+			xfunc_error_retval = 0;
 			bb_show_usage();
 		}
 	}