bnx2fc: do not scan uninitialized lists in case of error.

In case of of error, the bnx2fc_cmd_mgr_alloc() function will call
the bnx2fc_cmd_mgr_free() to perform the cleanup.
The problem is that in one case the latter may try to scan
some not-yet initialized lists, resulting in a kernel panic.

This patch prevents this from happening by freeing the lists
before calling bnx2fc_cmd_mgr_free().

Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Acked-by: Eddie Wai <eddie.wai@broadcom.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>