cxgb4: move handling L2T ARP failures to caller

commit 11d8cd5c upstream.

Move code handling L2T ARP failures to the only caller.

Fixes following sparse warning:
skbuff.h:2091:29: warning: context imbalance in
'handle_failed_resolution' - unexpected unlock

Fixes: 749cb5fe

 ("cxgb4: Replace arpq_head/arpq_tail with SKB double link-list code")
Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>