Depend on the linkerconfig binary in buildbot-build.sh.

This now picks the prebuilt linkerconfig binary on master-art, and the
source binary on the full platform branches.

Test: art/tools/buildbot-build.sh {--target,--host}
  on master-art and in AOSP master
Bug: 162819454
Change-Id: Ieee62aa683232659b07c647537339fe73de77077
diff --git a/tools/buildbot-build.sh b/tools/buildbot-build.sh
index 12271fa..34c1b4c 100755
--- a/tools/buildbot-build.sh
+++ b/tools/buildbot-build.sh
@@ -96,10 +96,8 @@
   make_command+=" ${ANDROID_PRODUCT_OUT#"${ANDROID_BUILD_TOP}/"}/system/etc/public.libraries.txt"
   # Targets required to generate a linker configuration for device within the
   # chroot environment. The *.libraries.txt targets are required by
-  # linkerconfig but not included in host_linkerconfig_all_targets. We cannot
-  # use linkerconfig, because building the device binary statically might not
-  # work in an unbundled tree.
-  make_command+=" host_linkerconfig_all_targets sanitizer.libraries.txt vndkcorevariant.libraries.txt"
+  # the source linkerconfig but not included in the prebuilt one.
+  make_command+=" linkerconfig sanitizer.libraries.txt vndkcorevariant.libraries.txt"
   # Additional targets needed for the chroot environment.
   make_command+=" event-log-tags"
   # Needed to extract prebuilt APEXes.