Add ! before unused variables to 'use' them.
Ubuntu-x64 emits warnings for unused variables because gcc decides
it should ignore the void cast around them. See thread for discussion:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66425
Loop index int i was being compared against GetControllerCount() which
returned a size_t. This was the only place GetControllerCount() was
called from so the change of return type doesn't disturb anything else.
Changing the loop index to size_t wouldn't work as well since it's
passed into GetController(), which takes an int and is called from many
places, so it would need a cast anyway on an already busy line.
DualShock UDP Client is the only place in the code that assumed OnConfigChanged()
is called at least once on startup or it won't load up the setting, so I took care of that
-If adding 2 devices with the same name, they their unique id wouldn't be increased, causing a conflict.
-Removing a device wouldn't actually remove it from the internal devices list because the list of devices had already been updated when going through it.
-It was possible to remove devices belonging to other sources by adding a device with the same name and then removing it.
