(2/2) zip: fix build in 7.1 tree with TW_USE_TOOLBOX

Zip repo in 7.1 tree already outputs to recovery ramdisk sbin folder,
and linker is set in the external/zip Android.mk file.
android_external_zip patch adjusts linker for both 32-bit
and 64-bit builds.

Change-Id: I5d6c6dac4cdd8ee4b4affd4b74305fbcb72d785e
diff --git a/prebuilt/Android.mk b/prebuilt/Android.mk
index a4f6f2e..e27f6cd 100644
--- a/prebuilt/Android.mk
+++ b/prebuilt/Android.mk
@@ -30,9 +30,6 @@
         ifeq ($(shell test $(PLATFORM_SDK_VERSION) -gt 23; echo $$?),0)
             RELINK_SOURCE_FILES += $(TARGET_RECOVERY_ROOT_OUT)/sbin/dd
         endif
-        ifneq ($(wildcard external/zip/Android.mk),)
-            RELINK_SOURCE_FILES += $(TARGET_OUT_OPTIONAL_EXECUTABLES)/zip
-        endif
         ifneq ($(wildcard external/unzip/Android.mk),)
             RELINK_SOURCE_FILES += $(TARGET_OUT_OPTIONAL_EXECUTABLES)/unzip
         endif