Fixed some JRPXSVF stuff and fixed a major bug in the MMCFlasher code... shouldn't read/write to the first sector all the time ;)

Signed-off-by: Swizzy <swizzy@hotmail.co.uk>
Revert to code that works in nandMMC but not x360NANDManager

Signed-off-by: Swizzy <swizzy@hotmail.co.uk>