Nothing you can do about it you can't access the PS3 without doing it and you can't access the HDD on a PC, so you just have to go ahead and bite the bullet, it's odd that it wants to format the drive but there must be a reason for it, try the recovery menu rebuild option first to see if it requires a format aswell but if it doe's then that's it.
Sorry to be the bearer of bad news but you could go around in circles for days listening to different opinions but in the end your still stuck with a paper weight until you do what the system wants.

