video: fbdev: kyro: remove set but not used 'ulBestVCO'

This addresses the following gcc warning with "make W=1":

drivers/video/fbdev/kyro/STG4000InitDevice.c: In function
‘ProgramClock’:
drivers/video/fbdev/kyro/STG4000InitDevice.c:123:6: warning: variable
‘ulBestVCO’ set but not used [-Wunused-but-set-variable]
123 | u32 ulBestVCO = 0, ulBestClk = 0, ulBestScore = 0;
| ^~~~~~~~~

Reported-by: Hulk Robot <[e-mail]>
Signed-off-by: Jason Yan <[e-mail]>
[b.zolnierkie: minor patch summary fixup]
Signed-off-by: Bartlomiej Zolnierkiewicz <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/video/fbdev/kyro/STG4000InitDevice.c

···
 {
 	u32 R = 0, F = 0, OD = 0, ODIndex = 0;
 	u32 ulBestR = 0, ulBestF = 0, ulBestOD = 0;
-	u32 ulBestVCO = 0, ulBestClk = 0, ulBestScore = 0;
+	u32 ulBestClk = 0, ulBestScore = 0;
 	u32 ulScore, ulPhaseScore, ulVcoScore;
 	u32 ulTmp = 0, ulVCO;
 	u32 ulScaleClockReq, ulMinClock, ulMaxClock;
···
 						ulScore = ulPhaseScore + ulVcoScore;
 
 						if (!ulBestScore) {
-							ulBestVCO = ulVCO;
 							ulBestOD = OD;
 							ulBestF = F;
 							ulBestR = R;
···
                           but we shall keep this code in case new restrictions come into play
                           --------------------------------------------------------------------------*/
 						if ((ulScore >= ulBestScore) && (OD > 0)) {
-							ulBestVCO = ulVCO;
 							ulBestOD = OD;
 							ulBestF = F;
 							ulBestR = R;