Avoid using "raise" to reraise with modified exception
Avoid using "raise" to reraise with modified exception

The code changes the exception and reraises it.
This commit changes the code to use the same way as
excutils.save_and_reraise_exception does to ensure
the exception context.

This is the last patch of reraise clean up series.

Closes-Bug: #1279813
Change-Id: I8787dcbdc8321f75964de26e97cae395707aafc2

gkotton/vmware-nsx,gkotton/vmware-nsx