Fixes a bug in _ExcEntSetupDone wherein the return address to the
exception stub was accidentally changed to point to the TCS of the
interrupted thread.
Jira: ZEP-378
Change-Id: I0e502649c49c35ba8b2457016ede4a6b586da3fb
Signed-off-by: Peter Mitsis <peter.mitsis@windriver.com>