Tag edit: metal_gear_solid_rising -> metal_gear_rising: revengeance

Game's old announced name should be replaced by the game's now official name.

Or shall we wait until the game is closer to release to make sure they've chosen a name?

It's an MGS subtitle, we can safely drop it since they have two per game minimum.

Agreed, the base tag is fine. Subtitles are often more for distinguishing sequels with otherwise the same base name.