video: fbdev: kyrofb: remove set but not used variable 'ulScaleRight'

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/video/fbdev/kyro/STG4000OverlayDevice.c: In function
‘SetOverlayViewPort’:
drivers/video/fbdev/kyro/STG4000OverlayDevice.c:334:19: warning:
variable ‘ulScaleRight’ set but not used [-Wunused-but-set-variable]

It is never used, and so can be removed.

Signed-off-by: yu kuai <yukuai3@huawei.com>
Cc: zhengbin <zhengbin13@huawei.com>
Cc: yi.zhang <yi.zhang@huawei.com>
[b.zolnierkie: minor patch summary fixup]
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200119121945.12517-1-yukuai3@huawei.com