pxa168fb: remove set but not used variables 'mi'

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

drivers/video/fbdev/pxa168fb.c: In function 'pxa168fb_set_par':
drivers/video/fbdev/pxa168fb.c:408:29: warning:
 variable 'mi' set but not used [-Wunused-but-set-variable]
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Cc: Lubomir Rintel <lkundrak@v3.sk>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

drivers/video/fbdev/pxa168fb.c

@@ -405,9 +405,6 @@ static int pxa168fb_set_par(struct fb_info *info)
 	struct fb_var_screeninfo *var = &info->var;
 	struct fb_videomode mode;
 	u32 x;
-	struct pxa168fb_mach_info *mi;
-
-	mi = dev_get_platdata(fbi->dev);
 
 	/*
 	 * Set additional mode info.