usb: dwb_otg: Fix unreachable switch statement warning

This warning appears with GCC 7.3.0 from toolchains.bootlin.com:

../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c: In function ‘fiq_fsm_update_hs_isoc’:
../drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c:595:61: warning: statement will never be executed [-Wswitch-unreachable]
   st->hctsiz_copy.b.xfersize = nrpackets * st->hcchar_copy.b.mps;
                                            ~~~~~~~~~~~~~~~~~^~~~

Signed-off-by: Nathan Chancellor <[email protected]>

drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c

@@ -591,8 +591,8 @@ static int notrace noinline fiq_fsm_update_hs_isoc(struct fiq_state *state, int
 		}
 
 	} else {
-		switch (st->hcchar_copy.b.multicnt) {
 		st->hctsiz_copy.b.xfersize = nrpackets * st->hcchar_copy.b.mps;
+		switch (st->hcchar_copy.b.multicnt) {
 		case 1:
 			st->hctsiz_copy.b.pid = DWC_PID_DATA0;
 			break;