misc: mic: double free on ioctl error path

This function only has one caller.  Freeing "vdev" here leads to a use
after free bug.  There are several other error paths in this function
but this is the only one which frees "vdev".  It looks like the kfree()
can be safely removed.

Fixes: 61e9c905 ("misc: mic: Enable VOP host side functionality")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>