Input: convert obsolete strict_strtox to kstrtox

With commit 67d0a0754455f89ef3946946159d8ec9e45ce33a we mark strict_strtox
as obsolete. Convert all remaining such uses in drivers/input/.

Also change long to appropriate types, and return error conditions
from kstrtox separately, as Dmitry sugguests.

Signed-off-by: JJ Ding <dgdunix@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
index d507b9b..c69536c 100644
--- a/drivers/input/touchscreen/ads7846.c
+++ b/drivers/input/touchscreen/ads7846.c
@@ -601,10 +601,12 @@
 				     const char *buf, size_t count)
 {
 	struct ads7846 *ts = dev_get_drvdata(dev);
-	unsigned long i;
+	unsigned int i;
+	int err;
 
-	if (strict_strtoul(buf, 10, &i))
-		return -EINVAL;
+	err = kstrtouint(buf, 10, &i);
+	if (err)
+		return err;
 
 	if (i)
 		ads7846_disable(ts);