ipv4: coding style: comparison for equality with NULL

The ipv4 code uses a mixture of coding styles. In some instances check
for NULL pointer is done as x == NULL and sometimes as !x. !x is
preferred according to checkpatch and this patch makes the code
consistent by adopting the latter form.

No changes detected by objdiff.

Signed-off-by: Ian Morris <ipm@chirality.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index 718b0a1..2166d2b 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -53,11 +53,11 @@
 	struct fib_table *local_table, *main_table;
 
 	main_table  = fib_trie_table(RT_TABLE_MAIN, NULL);
-	if (main_table == NULL)
+	if (!main_table)
 		return -ENOMEM;
 
 	local_table = fib_trie_table(RT_TABLE_LOCAL, main_table);
-	if (local_table == NULL)
+	if (!local_table)
 		goto fail;
 
 	hlist_add_head_rcu(&local_table->tb_hlist,
@@ -486,7 +486,7 @@
 			for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next)
 				if (strcmp(ifa->ifa_label, devname) == 0)
 					break;
-			if (ifa == NULL)
+			if (!ifa)
 				return -ENODEV;
 			cfg->fc_prefsrc = ifa->ifa_local;
 		}
@@ -514,7 +514,7 @@
 		int len = 0;
 
 		mx = kzalloc(3 * nla_total_size(4), GFP_KERNEL);
-		if (mx == NULL)
+		if (!mx)
 			return -ENOMEM;
 
 		if (rt->rt_flags & RTF_MTU)
@@ -676,7 +676,7 @@
 		goto errout;
 
 	tb = fib_get_table(net, cfg.fc_table);
-	if (tb == NULL) {
+	if (!tb) {
 		err = -ESRCH;
 		goto errout;
 	}
@@ -698,7 +698,7 @@
 		goto errout;
 
 	tb = fib_new_table(net, cfg.fc_table);
-	if (tb == NULL) {
+	if (!tb) {
 		err = -ENOBUFS;
 		goto errout;
 	}
@@ -779,7 +779,7 @@
 	else
 		tb = fib_new_table(net, RT_TABLE_LOCAL);
 
-	if (tb == NULL)
+	if (!tb)
 		return;
 
 	cfg.fc_table = tb->tb_id;
@@ -806,7 +806,7 @@
 
 	if (ifa->ifa_flags & IFA_F_SECONDARY) {
 		prim = inet_ifa_byprefix(in_dev, prefix, mask);
-		if (prim == NULL) {
+		if (!prim) {
 			pr_warn("%s: bug: prim == NULL\n", __func__);
 			return;
 		}
@@ -860,7 +860,7 @@
 
 	if (ifa->ifa_flags & IFA_F_SECONDARY) {
 		prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
-		if (prim == NULL) {
+		if (!prim) {
 			pr_warn("%s: bug: prim == NULL\n", __func__);
 			return;
 		}
@@ -1030,7 +1030,7 @@
 		return;
 
 	skb = netlink_skb_clone(skb, GFP_KERNEL);
-	if (skb == NULL)
+	if (!skb)
 		return;
 	nlh = nlmsg_hdr(skb);
 
@@ -1051,7 +1051,7 @@
 	};
 
 	sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg);
-	if (sk == NULL)
+	if (!sk)
 		return -EAFNOSUPPORT;
 	net->ipv4.fibnl = sk;
 	return 0;
@@ -1089,7 +1089,7 @@
 	case NETDEV_DOWN:
 		fib_del_ifaddr(ifa, NULL);
 		atomic_inc(&net->ipv4.dev_addr_genid);
-		if (ifa->ifa_dev->ifa_list == NULL) {
+		if (!ifa->ifa_dev->ifa_list) {
 			/* Last address was deleted from this interface.
 			 * Disable IP.
 			 */
@@ -1157,7 +1157,7 @@
 	size = max_t(size_t, size, L1_CACHE_BYTES);
 
 	net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL);
-	if (net->ipv4.fib_table_hash == NULL)
+	if (!net->ipv4.fib_table_hash)
 		return -ENOMEM;
 
 	err = fib4_rules_init(net);