dashboard: fix bootstrap path for s390x builder

Change-Id: I8d28dfdb18da11e64cd94c7d205990f64793fcc6
Reviewed-on: https://go-review.googlesource.com/20168
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
diff --git a/dashboard/builders.go b/dashboard/builders.go
index afd5485..3cbdd7c 100644
--- a/dashboard/builders.go
+++ b/dashboard/builders.go
@@ -583,7 +583,7 @@
 		Notes:          "run by IBM",
 		IsReverse:      true,
 		NumTestHelpers: 0,
-		env:            []string{"GOROOT_BOOTSTRAP=/var/buildlet/go-linux-ppc64le-bootstrap"},
+		env:            []string{"GOROOT_BOOTSTRAP=/var/buildlet/go-linux-s390x-bootstrap"},
 	})
 
 }