RDMA/cxgb4: fix accept failure due to increased cpl_t5_pass_accept_rpl size

Commit 'c2ed5611' has increased the cpl_t5_pass_accept_rpl{} structure
size by 8B to avoid roundup. cpl_t5_pass_accept_rpl{} is a HW specific
structure and increasing its size will lead to unwanted adapter errors.
Current commit reverts the cpl_t5_pass_accept_rpl{} back to its original
and allocates zeroed skb buffer there by avoiding the memset for iss field.
Reorder code to minimize chip type checks.

Fixes: c2ed5611

 ("iw_cxgb4: Use memset_startat() for cpl_t5_pass_accept_rpl")
Link: https://lore.kernel.org/r/20220809184118.2029-1-rahul.lakkireddy@chelsio.com
Signed-off-by: Potnuri Bharat Teja <bharat@chelsio.com>
Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Leon Romanovsky <leon@kernel.org>