qed: Fix memory/entry leak in qed_init_sp_request()

Free the allocated SPQ entry or return the acquired SPQ entry to the free
list in error flows.

Signed-off-by: Denis Bolotin <denis.bolotin@cavium.com>
Signed-off-by: Michal Kalderon <michal.kalderon@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>