gohbase: check if procedure finished with exception
gohbase: check if procedure finished with exception

A procedure can be marked finished both the it was successful and
failed. To actually check whether it completed successfully, the
exception needs to be checked.

Change-Id: I621a584c0af02346aaaf95333fd4f6d6ea1881d0

dougklein/gohbase,dougklein/gohbase,tsuna/gohbase