[WCNCR00170669] BT: Fix crash when fops_write

[Description]
User buff must copy to kernel by copy_from_user() before use it.

Change-Id: I85a931d27f7d6883a570a18a81fa6a146627ec4f
Signed-off-by: can.chen <can.chen@mediatek.com>
Feature: BT(MT7668)
CR-Id: WCNCR00170669
2 files changed