The original intent of 84d3f6b7 was to delay evaluating lid state until
all drivers have been loaded, with input device being opened from userspace
serving as a signal for this condition. Let's ensure that state updates
happen even if userspace closed (or in the future inhibited) input device.

Note that if we go through suspend/resume cycle we assume the system has
been fully initialized even if LID input device has not been opened yet.

This has a side-effect of fixing access to input->users outside of
input->mutex protections by the way of eliminating said accesses and using
driver private flag.

Fixes: 84d3f6b7 ("ACPI / button: Delay acpi_lid_initialize_state() until first user space open")
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Cc: 4.15+ <stable@vger.kernel.org> # 4.15+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>