ath6kl: return error code in ath6kl_wmi_set_roam_lrssi_cmd()

Propagate error code from failure of ath6kl_wmi_cmd_send() to the
caller.

Signed-off-by: Anirudh Rayabharam <mail@anirudhrb.com>
Cc: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20210503115736.2104747-44-gregkh@linuxfoundation.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>