Revision 354568

MFC r354116, r354120

r354116:
MFZoL:  Avoid retrieving unused snapshot props

This patch modifies the zfs_ioc_snapshot_list_next() ioctl to enable it
to take input parameters that alter the way looping through the list of
snapshots is performed. The idea here is to restrict functions that
throw away some of the snapshots returned by the ioctl to a range of
snapshots that these functions actually use. This improves efficiency
and execution speed for some rollback and send operations.

Reviewed-by: Tom Caputi <tcaputi@datto.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed by: Matt Ahrens <mahrens@delphix.com>
Signed-off-by: Alek Pinchuk <apinchuk@datto.com>
Closes #8077
zfsonlinux/zfs@4c0883fb4af0d5565459099b98fcf90ecbfa1ca1

r354120:
Commit missing file from r354116

Pointy-hat-to:	Me
Reported by:	Dan Mack
MFC-With:	354116