Code review comment for lp:~akopytov/percona-xtrabackup/test-suite-cleanups-2.0

One minor thing, line 1172 of the diff. run.sh sources ./inc/common.sh, then a few lines later sources the test which may (likely) also source ./inc/common.sh. Not a huge deal as they should both be sourcing the same file and common.sh doesn't do much of anything in the global space. If something changes in the future it could be possible for a test to potentially source a different common.sh or if any new scripting is added to the common.sh global space it would/could be executed twice possibly unknowingly causing some kind of issue.