usb: musb: fix bug in musb_cleanup_urb

Control transfers with data expected from device to host will use usb_rcvctrlpipe()
for urb->pipe so for such urbs 'is_in' will be set causing control urb to fall
into the first "if" condition in musb_cleanup_urb().

Fixed by adding logic to check for non control endpoints.

Signed-off-by: Ajay Kumar Gupta <ajay.gupta@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
index 79cb0af..ef8d744 100644
--- a/drivers/usb/musb/musb_host.c
+++ b/drivers/usb/musb/musb_host.c
@@ -2098,7 +2098,7 @@
 	}
 
 	/* turn off DMA requests, discard state, stop polling ... */
-	if (is_in) {
+	if (ep->epnum && is_in) {
 		/* giveback saves bulk toggle */
 		csr = musb_h_flush_rxfifo(ep, 0);