video: fbdev: pxa168fb: make pxa168fb_init_mode() return void

No other functions use the return value of pxa168fb_init_mode() and the
return value is always 0 now. Make it return void. This fixes the
following coccicheck warning:

drivers/video/fbdev/pxa168fb.c:565:5-8: Unneeded variable: "ret". Return
"0" on line 597
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
[fixed indent]
Link: https://patchwork.freedesktop.org/patch/msgid/20200506061745.19451-1-yanaijie@huawei.com

drivers/video/fbdev/pxa168fb.c

@@ -557,12 +557,11 @@ static const struct fb_ops pxa168fb_ops = {
 	.fb_imageblit	= cfb_imageblit,
 };
 
-static int pxa168fb_init_mode(struct fb_info *info,
+static void pxa168fb_init_mode(struct fb_info *info,
 			      struct pxa168fb_mach_info *mi)
 {
 	struct pxa168fb_info *fbi = info->par;
 	struct fb_var_screeninfo *var = &info->var;
-	int ret = 0;
 	u32 total_w, total_h, refresh;
 	u64 div_result;
 	const struct fb_videomode *m;
@@ -593,8 +592,6 @@ static int pxa168fb_init_mode(struct fb_info *info,
 	div_result = 1000000000000ll;
 	do_div(div_result, total_w * total_h * refresh);
 	var->pixclock = (u32)div_result;
-
-	return ret;
 }
 
 static int pxa168fb_probe(struct platform_device *pdev)