staging: fbtft: fb_ssd1306: Refactor write_vmem()

Refactor write_vmem() for sake of readability.

While here, fix indentation in one comment.
Acked-by: Noralf Trønnes <noralf@tronnes.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/fbtft/fb_ssd1306.c

@@ -84,7 +84,7 @@ static int init_display(struct fbtft_par *par)
 	/* Vertical addressing mode  */
 	write_reg(par, 0x01);
 
-	/*Set Segment Re-map */
+	/* Set Segment Re-map */
 	/* column address 127 is mapped to SEG0 */
 	write_reg(par, 0xA0 | 0x1);
 
@@ -183,26 +183,24 @@ static int set_gamma(struct fbtft_par *par, unsigned long *curves)
 static int write_vmem(struct fbtft_par *par, size_t offset, size_t len)
 {
 	u16 *vmem16 = (u16 *)par->info->screen_buffer;
+	u32 xres = par->info->var.xres;
+	u32 yres = par->info->var.yres;
 	u8 *buf = par->txbuf.buf;
 	int x, y, i;
 	int ret = 0;
 
-	for (x = 0; x < par->info->var.xres; x++) {
-		for (y = 0; y < par->info->var.yres/8; y++) {
+	for (x = 0; x < xres; x++) {
+		for (y = 0; y < yres / 8; y++) {
 			*buf = 0x00;
 			for (i = 0; i < 8; i++)
-				*buf |= (vmem16[(y * 8 + i) *
-						par->info->var.xres + x] ?
-					 1 : 0) << i;
+				*buf |= (vmem16[(y * 8 + i) * xres + x] ? 1 : 0) << i;
 			buf++;
 		}
 	}
 
 	/* Write data */
 	gpio_set_value(par->gpio.dc, 1);
-	ret = par->fbtftops.write(par, par->txbuf.buf,
-				  par->info->var.xres * par->info->var.yres /
-				  8);
+	ret = par->fbtftops.write(par, par->txbuf.buf, xres * yres / 8);
 	if (ret < 0)
 		dev_err(par->info->device, "write failed and returned: %d\n",
 			ret);