Fix and reenable clone_001_pos

tests/sys/cddl/zfs/include/libtest.kshlib
Declare local variables

tests/sys/cddl/zfs/snapshot/clone_001_pos.ksh

• Remove a Solarism
• Remove extraneous teardown steps
• Don't autofail on FreeBSD

tests/sys/cddl/zfs/snapshot/snapshot_test.sh
Clear an expected failure, and skip if vfs.zfs.vol.recursive=0

Submitted by: avg
Sponsored by: Spectra Logic Corp