commit cc71b7b0 ("net/ipv6: remove unused err variable on
icmpv6_push_pending_frames") exposed icmpv6_push_pending_frames
return value not being used.

Remove now unnecessary int err declarations and uses.

Miscellanea:

o Remove unnecessary goto and out: labels
o Realign arguments
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>