Commit 4eaf99be

 switched to returning bool and as a result reversed
the logic of the integrity merge checks.  However, the empty stubs used
when the block integrity code is compiled out were still returning
0. Make these stubs return "true".

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reported-by: Michael L. Semon <mlsemon35@gmail.com>
Tested-by: Michael L. Semon <mlsemon35@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>