fix tapenabler return code

if tap enable/disable failed then a warning was written to the log, but JIM_OK was returned. if using openocd via a TCP interface to the TCL port, there is no way to catch that the command failed (it didn't enable the tap, so it failed)
now it return an error if it fails.

src/jtag/tcl.c

@@ -774,11 +774,15 @@ static int jim_jtag_tap_enabler(Jim_Interp *interp, int argc, Jim_Obj *const *ar
 	if (strcasecmp(cmd_name, "tapisenabled") == 0) {
 		// do nothing, just return the value
 	} else if (strcasecmp(cmd_name, "tapenable") == 0) {
-		if (!jtag_tap_enable(t))
+		if (!jtag_tap_enable(t)){
 			LOG_WARNING("failed to enable tap %s", t->dotted_name);
+                        return JIM_ERR;
+                }
 	} else if (strcasecmp(cmd_name, "tapdisable") == 0) {
-		if (!jtag_tap_disable(t))
+		if (!jtag_tap_disable(t)){
 			LOG_WARNING("failed to disable tap %s", t->dotted_name);
+                        return JIM_ERR;
+                }
 	} else {
 		LOG_ERROR("command '%s' unknown", cmd_name);
 		return JIM_ERR;