gpioc: cleanup if pin allocation fails

gpioc normally depends on gpioc_cdevpriv_dtor to call
gpioc_release_pin_intr when it's done with a pin. However, if
gpioc_allocate_pin_intr fails, the pin is never added to the linked list
which the destructor loops over to free the pins. Make it so
gpioc_allocate_pin_intr cleans up after itself if it fails.

Reported by:	Evgenii Ivanov <[email protected]>
Approved by:	imp (mentor, implicit)
Differential Revision:	https://reviews.freebsd.org/D51998

Author: VexedUXR

sys/dev/gpio/gpioc.c

@@ -208,8 +208,11 @@ gpioc_allocate_pin_intr(struct gpioc_pin_intr *intr_conf, uint32_t flags)
 	err = bus_setup_intr(intr_conf->pin->dev, intr_conf->intr_res,
 	    INTR_TYPE_MISC | INTR_MPSAFE, NULL, gpioc_interrupt_handler,
 	    intr_conf, &intr_conf->intr_cookie);
-	if (err != 0)
+	if (err != 0) {
+		bus_release_resource(sc->sc_dev, intr_conf->intr_res);
+		intr_conf->intr_res = NULL;
 		goto error_exit;
+	}
 
 	intr_conf->pin->flags = flags;