Use the installed vboot_signer.

Bug: 34738751
Test: Set `PRODUCT_SUPPORTS_VBOOT := true` and `m -j otatools-package`.
      Check the packed tools.
Test: Set `PRODUCT_SUPPORTS_VBOOT := true` and `m -j bootimage`.
Change-Id: Ia2ea475e3dc03cada1da524a299a21b8ad7ed536
diff --git a/core/config.mk b/core/config.mk
index bf59fb1..1db37ef 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -608,7 +608,7 @@
 BUILD_VERITY_TREE := $(HOST_OUT_EXECUTABLES)/build_verity_tree
 BOOT_SIGNER := $(HOST_OUT_EXECUTABLES)/boot_signer
 FUTILITY := $(HOST_OUT_EXECUTABLES)/futility-host
-VBOOT_SIGNER := prebuilts/misc/scripts/vboot_signer/vboot_signer.sh
+VBOOT_SIGNER := $(HOST_OUT_EXECUTABLES)/vboot_signer
 FEC := $(HOST_OUT_EXECUTABLES)/fec
 BRILLO_UPDATE_PAYLOAD := $(HOST_OUT_EXECUTABLES)/brillo_update_payload