mem-ruby: Fix cache hits being profiled as cache misses

mem-ruby: Fix cache hits being profiled as cache misses

There are some instances where a cache hit is profiled as a cache
miss. This commit addresses this error.

Change-Id: I7dafa806ef3f1e3717650dc25f8657a0ea741dd1
Signed-off-by: Hoa Nguyen <hoanguyen@ucdavis.edu>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/37835
Reviewed-by: Matt Sinclair <mattdsinclair@gmail.com>
Reviewed-by: Daniel Gerzhoy <daniel.gerzhoy@gmail.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Matt Sinclair <mattdsinclair@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>