If the files being relocated are already used by other processes the
relocate script will fail with a traceback. This patch will trap any IO
errors when opening such a file and gracefully report them to the user.
Also change the exit code from 1 to -1 for a better adt-installer user
experience (like pointing the user to the adt_installer.log).
[YOCTO #3164]
Signed-off-by: Laurentiu Palcu <laurentiu.palcu@intel.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
