fbsplash: fix regression from e4fa7b7

commit e4fa7b7 (limit progress bar flicker) made the progress bar
counter unsigned causing i < 0 to never come true.

Signed-off-by: Timo Teräs <timo.teras@iki.fi>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
1 file changed