Avoid a tautological bitwise compare.

This looks like a bit of debugging code that sliped into the initial
import of the new ATA framework. This changes the behavior to omit a
line of output that appears to have been intended for omission.

Reviewed by: mav
MFC after: 3 days
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D22845