netfilter: Add missing vmalloc.h include to nft_hash.c

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/netfilter/nft_hash.c

@@ -14,6 +14,7 @@
 #include <linux/list.h>
 #include <linux/jhash.h>
 #include <linux/netlink.h>
+#include <linux/vmalloc.h>
 #include <linux/netfilter.h>
 #include <linux/netfilter/nf_tables.h>
 #include <net/netfilter/nf_tables.h>