video: fbdev: sstfb: replace spurious snprintf() with sprintf()

video: fbdev: sstfb: replace spurious snprintf() with sprintf()

par->vgapass is a u8, so if we are assuming that buf is at least
PAGE_SIZE then the extra checking is pointless.

Signed-off-by: Alex Dewar <alex.dewar90@gmail.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
[b.zolnierkie: minor patch summary fixup]
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200824174407.429817-1-alex.dewar90@gmail.com