mei: constify struct file pointer

The struct file file pointer is used as an opaque handle to for a
connected client, for this part the pointer should be immutable and
should be set to count.

Reviewed-by: Alexander Usyskin <[email protected]>
Signed-off-by: Tomas Winkler <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
5 files changed