Remove interval for XInput rumbles

[bslenul]

Description

As mentioned here: #17954 (comment) the added interval added in the XInput rumble mechanism breaks rumble (e.g. when a game/core requests start/stop for both weak and strong rumbles at the same time).
This PR simply removes that interval while keeping the "if rumble hasn't changed, return before calling g_XInputSetState()" logic which was the main reason for improved performances.

edit: Unrelated but also silenced a warning about has_active_ports being initialized but not used.

Related Issues

Fixes #18172

Related Pull Requests

#17954

Reviewers

@Ryunam @sonninnos would you mind testing on your end? I tested with multiple cores (especially mGBA as mentioned in Ryunam's PR) and didn't notice any difference in FPS.

[sonninnos]

Seems fine here, as in rumble issue is gone, and no noticeable change in FF speeds with and without controller connected.

[Ryunam]

Thank you so much for taking the time to investigate this and devise a fix!
I'll have time to test this today in the evening (in about 8 hours from now) and will report back here.

[Ryunam]

@bslenul Okay, I took the time to test this. For the most part - pretty much 99% of the core-content combinations that I have tried so far - I do not see performance regressions, so that's great!

There's just one very niche situation though that I have found, which might be a core-specific issue and not really a frontend one.
Using the mgba core and playing the game "Drill Dozer", notable for having native rumble compatibility, try to go past the introduction sequence and reach the first in-game section.
Then, mash/press/hold the R button to activate the drilling ability of the character (which also triggers a rumble effect), all while holding the fastforward hotkey.

This is the FF framerate before this PR:

This is the FF framerate with the changes introduced in this PR:

I wonder if, instead of outright removing the interval, it could be reworked differently to accommodate both the strong/weak motors?

[bslenul]

I wonder if, instead of outright removing the interval, it could be reworked differently to accommodate both the strong/weak motors?

Idk how to handle that OOT case tho, if there's any kind of interval it won't stop rumbling on boot/area change, or we'd have to change it to microseconds but I doubt it'd make any difference with no interval at all at that point :p