Fix a linking error in bionic/tests

Fix the following linking error by adding liblog in the makefile:
"system/core/libziparchive/zip_archive.cc:277: error: undefined reference to
'__android_log_error_write'"

The error happens because libziparchive has dependency on liblog. This
error affects the downstream branches of nyc-dev.

Bug: 31251826
Test: mma -j32
Change-Id: Ia42909bbbd150ae0ca9f6aa6b14372f2e0aedccf
(cherry picked from commit 3656958a)

tests/Android.mk

@@ -319,6 +319,7 @@ common_bionic-unit-tests_shared_libraries_target := \
 common_bionic-unit-tests_static_libraries_target := \
     libbase \
     libziparchive \
+    liblog \
     libz \
     libutils \