SourceForge in particular doesn't like multiple connections from the
same IP, but when a source mirror is being populated for the first time
this will happen. Our fetch falls back to the Yocto mirror so it doesn't
cause a failure, but there is a warning logged which our CI then fails
because of.
As we don't care about these warnings, filter them out of the log before
checking if there were any errors.
Change-Id: I36c97c5d9923f1c4d14c4588f3780211cccb57b2
Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Jon Mason <jon.mason@arm.com>
a915532234