Add and use fixup_exception helper function in order to remove the
duplicated exception handler fixup code at several places.
Reviewed-by: NAlexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: NHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: NVasily Gorbik <gor@linux.ibm.com>