wlcore: fix runtime pm imbalance in __wl1271_op_remove_interface

When wl12xx_cmd_role_disable() returns an error code,
a pairing runtime PM usage counter decrement is needed to
keep the counter balanced.

Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200520130806.14789-1-dinghao.liu@zju.edu.cn