block: replace strict_strtoul() with kstrtoul()

The use of strict_strtoul() is not preferred, because strict_strtoul() is
obsolete.  Thus, kstrtoul() should be used.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 39c51cc..b22a7d0 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -5132,7 +5132,7 @@
 	bool already = false;
 	int ret;
 
-	ret = strict_strtoul(buf, 10, &ul);
+	ret = kstrtoul(buf, 10, &ul);
 	if (ret)
 		return ret;