dynamic_debug: replace obselete simple_strtoul() with kstrtouint()

Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Jason Baron <jbaron@akamai.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index e488d9a..7288e38 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -268,14 +268,12 @@
  */
 static inline int parse_lineno(const char *str, unsigned int *val)
 {
-	char *end = NULL;
 	BUG_ON(str == NULL);
 	if (*str == '\0') {
 		*val = 0;
 		return 0;
 	}
-	*val = simple_strtoul(str, &end, 10);
-	if (end == NULL || end == str || *end != '\0') {
+	if (kstrtouint(str, 10, val) < 0) {
 		pr_err("bad line-number: %s\n", str);
 		return -EINVAL;
 	}