wil6210: fix memory leak on error path in wil_write_file_rxon()

If copy_from_user() fails, buffer allocated for parameters would leak

Signed-off-by: Vladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --cc drivers/net/wireless/ath/wil6210/debugfs.c
Simple merge