ipv6: coding style improvements (remove assignment in if statements)

This change has no functional impact and simply addresses some coding
style issues detected by checkpatch. Specifically this change
adjusts "if" statements which also include the assignment of a
variable.

No changes to the resultant object files result as determined by objdiff.

Signed-off-by: Ian Morris <ipm@chirality.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 251fcb4..9eac3a7 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -2543,7 +2543,8 @@
 	if (!dev)
 		return -ENODEV;
 
-	if ((idev = __in6_dev_get(dev)) == NULL)
+	idev = __in6_dev_get(dev);
+	if (idev == NULL)
 		return -ENXIO;
 
 	read_lock_bh(&idev->lock);
@@ -2690,7 +2691,8 @@
 
 	ASSERT_RTNL();
 
-	if ((idev = ipv6_find_idev(dev)) == NULL) {
+	idev = ipv6_find_idev(dev);
+	if (idev == NULL) {
 		pr_debug("%s: add_dev failed\n", __func__);
 		return;
 	}
@@ -2813,7 +2815,8 @@
 	 * our v4 addrs in the tunnel
 	 */
 
-	if ((idev = ipv6_find_idev(dev)) == NULL) {
+	idev = ipv6_find_idev(dev);
+	if (idev == NULL) {
 		pr_debug("%s: add_dev failed\n", __func__);
 		return;
 	}
@@ -2837,7 +2840,8 @@
 
 	ASSERT_RTNL();
 
-	if ((idev = ipv6_find_idev(dev)) == NULL) {
+	idev = ipv6_find_idev(dev);
+	if (idev == NULL) {
 		pr_debug("%s: add_dev failed\n", __func__);
 		return;
 	}