mem-cache: Fix double block invalidation

mem-cache: Fix double block invalidation

Block was being invalidated twice when not a tempBlock.
Make explicit that the else case is only to be applied
when handling the tempBlock, as otherwise the Tags
should be taking care of the invalidation.

Change-Id: Ie7603fdbe156c54e94bbdc83541b55e66f8d250f
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/13895
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>