bna: Fix set-but-unused variables.

The variable 'pgoff' is set but unused in bfa_nw_ioc_fwver_get()
and bfa_ioc_download_fw().

Similarly for 'cmd_h' in bna_mbox_flush_q and the entirety of
bna_rit_mod_uninit() is unused since variables are purely set but no
action is made using them.

Same for 'bna' in bna_rit_create() and 'ret' in bna_rx_create().

Just kill them off.

Signed-off-by: David S. Miller <davem@davemloft.net>