Deprecated SNAPOID_SNAPNAME includes target

[sTywin]

In version 2.0.3, the snapshot name environment variable did not include the target or @ symbol:

SANOID_SNAPNAME='autosnap_2023-02-06_03:00:06_hourly'

Since upgrading to 2.1.0, the now-deprecated snapshot name includes the target:

SANOID_SNAPNAME='rpool/archive/vmail@autosnap_2023-02-06_03:00:06_hourly'

I am working on updating my post-snapshot script to handle the new SANOID_SNAPNAMES (and SANOID_TARGETS) variables, but that will take a bit of time. It's not clear if this change was intentional or not. Note that the documentation in README.md indicates that the SANOID_SNAPNAME variable should not include the target:

sanoid/README.md

Line 204 in ef601eb

SANOID_SNAPNAME=autosnap_2020-02-12_14:49:32_yearly