are linked with libraries they don't use:
- zinject doesn't use libavl
- ztest doesn't use libz
- zdb uses neither libavl nor libz
- zfs uses neither libbsdxml nor libm, nor libsbuf
- zpool uses neither libbsdxml nor libm, nor libsbuf
In addition, libzfs needs libm because it uses pow(), however it isn't
linked with -lm. This went unnoticed because all its users had -lm before.
Reviewed by: pjd, mm
Approved by: kib (mentor)
MFC after: 1 week