staging/xgifb: Fix always false condition in vb_setmode.c (smatch)

Smatch complains:
drivers/staging/xgifb/vb_setmode.c:3181
XGI_SetLockRegs() warn: bitwise AND condition is false here

Since SetNTSCTV is defined as 0 in drivers/video/sis/initdef.h this is
correct.
-> Change the condition to == to fix this.
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/xgifb/vb_setmode.c

@@ -3178,7 +3178,7 @@ static void XGI_SetLockRegs(unsigned short ModeNo, unsigned short ModeIdIndex,
 	if (pVBInfo->VBInfo & SetCRT2ToTV) {
 		if (pVBInfo->TVInfo & TVSimuMode) {
 			if (ModeNo == 0x50) {
-				if (pVBInfo->TVInfo & SetNTSCTV) {
+				if (pVBInfo->TVInfo == SetNTSCTV) {
 					xgifb_reg_set(pVBInfo->Part1Port,
 							0x07, 0x30);
 					xgifb_reg_set(pVBInfo->Part1Port,