cmd/bent: don't clean cache, use -a always instead.

Build caching changed in 1.20, and building after a cleaned cache now
takes much much longer, no longer reflects typical user experience,
and is incomparable with earlier releases.  This should have been the
choice all along.

Change-Id: Idc3200d0b5d9cee4afd017abc111b2a9051aa0a9
Reviewed-on: https://go-review.googlesource.com/c/benchmarks/+/452595
Run-TryBot: David Chase <drchase@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
1 file changed