Update user_io.cpp

[rikard-softgear]

Use all progress chars to render the progress bar.

[sorgelig]

More chars may slow down loading.

[rikard-softgear]

I didn't notice such a thing.

[birdybro]

Tested with Final Fantasy Tactics Advance with GBA core (long load time for this game). No major difference in load times (the equivalent of being 2 frames ahead of the load animation by the end for the original, but I have not ruled out this being influenced by variation of load times if there are any, due to microSD and other factors).

fftacomparison.mp4

Tested with a much smaller game, Sonic 2 for Sega Genesis, again no real difference in load times that I can tell.

sonic2comparison.mp4

I see no evidence that this increases load times in any serious way.

EDIT: forgive my crappy video editing skills, these are not synced to an exact frame perfectly.