base-stats: Print the name of stats sharing the same name

base-stats: Print the name of stats sharing the same name

Having stats of the same name within the same group result in an error.
This commit adds the name to the error message to make it easier to find
the Stats::Group caused the error.

Change-Id: I4010d5d949d1c943d2dd1e2fca0aafcbf62e3ee1
Signed-off-by: Hoa Nguyen <hoanguyen@ucdavis.edu>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/38337
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>