src: update buildall.bash comment with renamed trybot builder

Change-Id: I77887d247d3e5d60305fc76f962652268827b955
Reviewed-on: https://go-review.googlesource.com/9516Reviewed-by: David Crawshaw <crawshaw@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>

src/buildall.bash

@@ -6,8 +6,8 @@
 # Usage: buildall.sh [-e] [pattern]
 #
 # buildall.bash builds the standard library for all Go-supported
-# architectures. It is used by the linux-amd64-compilesmoke trybot
-# builder, as a smoke test to quickly flag portability issues.
+# architectures. It is used by the "all-compile" trybot builder,
+# as a smoke test to quickly flag portability issues.
 #
 # Options:
 #   -e: stop at first failure