pinctrl: sprd: Use seq_putc() in sprd_pinconf_group_dbg_show()

A single character (line break) should be put into a sequence.
Thus use the corresponding function "seq_putc".

This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/sprd/pinctrl-sprd.c

@@ -818,7 +818,7 @@ static void sprd_pinconf_group_dbg_show(struct pinctrl_dev *pctldev,
 
 	grp = &info->groups[selector];
 
-	seq_printf(s, "\n");
+	seq_putc(s, '\n');
 	for (i = 0; i < grp->npins; i++, config++) {
 		unsigned int pin_id = grp->pins[i];