oe-build-perf-report: Allow commits from different branches
The code won't currently allow comparisions of two commits on different
branches even if the commits are specified by their hashes.
This updates the code to search two branches for any relavent commits,
hence allowing comparisions to be made. A particularly useful case is
master vs. master-next for example.
(From OE-Core rev:
2d835bb1570c515ae501442f3ce19fae8e249b27)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Armin Kuster <akuster808@gmail.com>
