USB: musb_gadget: fix kernel oops in txstate()

Commit 7723de7e19b744144975a09c81777ec0f14ac5b3 (USB: musb_gadget: remove
pointless loop) included uncalled for (and incorrect) optimization that
might cause a kernel oops in txstate() -- undo it.

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/musb/musb_gadget.c

@@ -515,12 +515,12 @@ void musb_g_tx(struct musb *musb, u8 epnum)
 			if (csr & MUSB_TXCSR_FIFONOTEMPTY)
 				return;
 
-			if (!musb_ep->desc) {
+			request = musb_ep->desc ? next_request(musb_ep) : NULL;
+			if (!request) {
 				DBG(4, "%s idle now\n",
 					musb_ep->end_point.name);
 				return;
-			} else
-				request = next_request(musb_ep);
+			}
 		}
 
 		txstate(musb, to_musb_request(request));