net: Remove unnecessary returns from void function()s

This patch removes from net/ (but not any netfilter files)
all the unnecessary return; statements that precede the
last closing brace of void functions.

It does not remove the returns that are immediately
preceded by a label as gcc doesn't like that.

Done via:
$ grep -rP --include=*.[ch] -l "return;\n}" net/ | \
  xargs perl -i -e 'local $/ ; while (<>) { s/\n[ \t\n]+return;\n}/\n}/g; print; }'

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/xfrm/xfrm_policy.c

@@ -2209,7 +2209,6 @@ EXPORT_SYMBOL(xfrm_dst_ifdown);
 static void xfrm_link_failure(struct sk_buff *skb)
 {
 	/* Impossible. Such dst must be popped before reaches point of failure. */
-	return;
 }
 
 static struct dst_entry *xfrm_negative_advice(struct dst_entry *dst)