The AbortFn() used to overwrite the error message, hiding the real
failure reported in ErrorAbort(). And we will miss the failure in
the script patterns like 'blockimageupdate() || abort()'
We will ensure there's one line break at the end of ErrorAbort's
error message; and append to the existing error message when calling
abort().
Test: Message from ErrorAbort shows up in the log
Change-Id: I3aebd06629c5129330250c7fe5e8cdead2ae85bc
5ad802839d