pkg: Return error when installation fails
pkg: Return error when installation fails

When an error happened during replacing the executables, the error was
printed, but no error was returned. This caused SF to think that
everything went ok.

This patch changes that and makes sure that an error is returned.

Change-Id: 73ec4311d1
Story-Id: SF-188

salsaflow/salsaflow,salsaflow/salsaflow