buildhistory: filter out the unexpected prefix for native/cross sysroots
For various technical reasons, native and cross builds have a prefix that
includes the full path to the sysroot. As these are stripped away before the
files are used in the sysroot, we should also filter them out of the
buildhistory report. This both removes noise when sharing a buildhistory
repository between different build directories, and improves the accuracy of the
reports.
Signed-off-by: Ross Burton <ross.burton@intel.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
