increase reserved blocks from 5 to 8
increase reserved blocks from 5 to 8

Our yaffs filesystems reserve 5 blocks, use 1 for a checkpoint, and
may use 1 or 2 more for caching.  Take these all into account when
computing the max image size.

fallouttester/platform_manifest,xorware/android_build,pranav01/platform_manifest,knone1/platform_manifest,xorware/android_build,Hybrid-Power/startsync,ND-3500/platform_manifest,xorware/android_build,hagar006/platform_manifest,xorware/android_build,see4ri/lolili,xorware/android_build,RR-msm7x30/platform_manifest