HID: usbhid: protect hid disconnect flag

HID: usbhid: protect hid disconnect flag

Acquire spin_lock before checking disconnect flag of hid.
Also add USB interface null check at get_raw_report.

Bug 200018305

Change-Id: I7255fa641cabf0866dd0d1f2fdab460ec82eca70
Signed-off-by: Vinayak Pane <vpane@nvidia.com>
Reviewed-on: http://git-master/r/434584
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Robert Shih <rshih@nvidia.com>
Tested-by: Robert Shih <rshih@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-by: Eric Chuang <echuang@nvidia.com>