HID: logitech-hidpp: rework hidpp_connect_event()

Looks like all users don't care about a disconnect.
Simplify the various variant_connect() and put the connect state check
at the beginning.

For delayed input devices, make sure we go through all other connect
values (protocol, battery) before bailing out.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Tested-by: Bastien Nocera <hadess@hadess.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>