Update libblkmaker to 0.2.2
Bump version to 2.9.8
Revert "x6500: Whenever we get a hardware error, purge buffers just in case of read/write desync"

This reverts commit 816c777022bc255059fe6c6bdd7528d293c3086a.

Conflicts:
	driver-x6500.c
Merge commit '6cb9320' into bfgminer-2.9.x
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