netfilter: conntrack: remote a return value of the 'seq_print_acct' function.

netfilter: conntrack: remote a return value of the 'seq_print_acct' function.

The static 'seq_print_acct' function always returns 0.

Change the return value to 'void' and remove unnecessary checks.

Found by InfoTeCS on behalf of Linux Verification Center
(linuxtesting.org) with SVACE.

Fixes: 1ca9e41770cb ("netfilter: Remove uses of seq_<foo> return values")
Signed-off-by: Ilia.Gavrilov <[email protected]>
Reviewed-by: Leon Romanovsky <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>