misc: mic: Release reference count and memory for VOP device

Never directly free @dev after calling device_register(),
even if it returned an error! Always use put_device() to
give up the reference initialized.
Release allocated memory for vop device in vop_release_dev().

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>