lttng-tools: bump to 2.1.0

* add patch adding src/bin/lttng-sessiond/lttng-ust-error.h which is
  missing in the lttng-tools-2.1.0 release tarball.
* update the sync_file_range patch.

Signed-off-by: Samuel Martin <s.martin49@gmail.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>