isdn: eicon: Fix set-but-unused variables.

The variable 'best_id' is set but unused in
diva_mnt_add_xdi_adapter().  Just kill it off.

Similarly for the variable 'CIP' in connect_req(), 'Number' in
sig_ind(), 'Info' in dtmf_confirmation() mixer_command()
fax_connect_ack_command() fax_edata_ack_command()
rtp_connect_b3_res_command() and rtp_connect_b3_res_command(), and 'a'
in mixer_indication_coefs_set(),

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