tools/cephfs: Clean up waits in Dumper

Remove some LOC by using C_SaferCond.

Signed-off-by: John Spray <john.spray@inktank.com>
tools/cephfs: error handling in journal_export

Was failing on unreadable journal even if
only trying to do an import.

Was calling messenger destructor without init
on early failures due to early instantiation
of Dumper.

Signed-off-by: John Spray <john.spray@inktank.com>
tools/cephfs: Purge trailing objects during import

Reviewed-by: Gregory Farnum <greg@inktank.com>
Signed-off-by: John Spray <john.spray@inktank.com>
qa: set +x on cephfs_journal_tool_smoke

Signed-off-by: John Spray <john.spray@redhat.com>
qa: extend cephfs_journal_tool_smoke

To provide coverage for the 'import' command
resulting in the same contents as before an
export/import cycle.

Signed-off-by: John Spray <john.spray@redhat.com>
Merge pull request #1947 from ceph/wip-import-purge

Wip import purge

Reviewed-by: Greg Farnum <greg@inktank.com>