fbdev: panel-tpo-td043mtea1: Convert sprintf() to sysfs_emit()

Per filesystems/sysfs.rst, show() should only use sysfs_emit()
or sysfs_emit_at() when formatting the value to be returned to user space.

coccinelle complains that there are still a couple of functions that use
snprintf(). Convert them to sysfs_emit().

CC: Helge Deller <deller@gmx.de>
CC: linux-omap@vger.kernel.org
CC: linux-fbdev@vger.kernel.org
CC: dri-devel@lists.freedesktop.org
Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
Signed-off-by: Helge Deller <deller@gmx.de>

drivers/video/fbdev/omap2/omapfb/displays/panel-tpo-td043mtea1.c

@@ -225,17 +225,12 @@ static ssize_t tpo_td043_gamma_show(struct device *dev,
 {
 	struct panel_drv_data *ddata = dev_get_drvdata(dev);
 	ssize_t len = 0;
-	int ret;
 	int i;
 
-	for (i = 0; i < ARRAY_SIZE(ddata->gamma); i++) {
-		ret = snprintf(buf + len, PAGE_SIZE - len, "%u ",
-				ddata->gamma[i]);
-		if (ret < 0)
-			return ret;
-		len += ret;
-	}
-	buf[len - 1] = '\n';
+	for (i = 0; i < ARRAY_SIZE(ddata->gamma); i++)
+		len += sysfs_emit_at(buf, len, "%u ", ddata->gamma[i]);
+	if (len)
+		buf[len - 1] = '\n';
 
 	return len;
 }