net: fix compile error of leaking kmemleak.h header

net/core/sysctl_net_core.c: In function ‘sysctl_core_init’:
net/core/sysctl_net_core.c:259: error: implicit declaration of function ‘kmemleak_not_leak’

with same error in net/ipv4/route.c

Signed-off-by: Shan Wei <davidshan@tencent.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index bcd4744..a1c115d 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -109,6 +109,7 @@
 #include <net/rtnetlink.h>
 #ifdef CONFIG_SYSCTL
 #include <linux/sysctl.h>
+#include <linux/kmemleak.h>
 #endif
 #include <net/secure_seq.h>