USB: musb_gadget_ep0: fix typo in service_zero_data_request()

This function uses wrong bit mask to prevent clearing RXCSR status
bits when halting an endpoint -- which results in clearing SentStall
and RxPktRdy bits (that the code actually tries to avoid); must be
a result of cut-and-paste...
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/musb/musb_gadget_ep0.c

@@ -407,7 +407,7 @@ __acquires(musb->lock)
 					csr |= MUSB_RXCSR_P_SENDSTALL
 						| MUSB_RXCSR_FLUSHFIFO
 						| MUSB_RXCSR_CLRDATATOG
-						| MUSB_TXCSR_P_WZC_BITS;
+						| MUSB_RXCSR_P_WZC_BITS;
 					musb_writew(regs, MUSB_RXCSR,
 							csr);
 				}