drm/imx: prefer snprintf over sprintf

This will trade the W=1 warning -Wformat-overflow to
-Wformat-truncation. This lets us enable -Wformat-overflow subsystem
wide.

Cc: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/14c0108a54007a8360d84162a1d63cba9613b945.1704908087.git.jani.nikula@intel.com

drivers/gpu/drm/imx/ipuv3/imx-ldb.c

@@ -655,7 +655,7 @@ static int imx_ldb_probe(struct platform_device *pdev)
 	for (i = 0; i < 4; i++) {
 		char clkname[16];
 
-		sprintf(clkname, "di%d_sel", i);
+		snprintf(clkname, sizeof(clkname), "di%d_sel", i);
 		imx_ldb->clk_sel[i] = devm_clk_get(imx_ldb->dev, clkname);
 		if (IS_ERR(imx_ldb->clk_sel[i])) {
 			ret = PTR_ERR(imx_ldb->clk_sel[i]);