Tweak the gitarchive exclude handling not to error if excluded files
don't match.
Also return the tagname created so that other code can then use it.
(From OE-Core rev: 0a5b4fabf8bf9b559295bb4d2583809ca11522f4)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
(cherry picked from commit 1adba3430faffdf6217b6a00533a3b48a9388abc)
Signed-off-by: Steve Sakoman <steve@sakoman.com>