Don't explicitly link gtest.

The build system does this for us. Since libgtest is the stlport
version of the library, this causes build breakages when libc++ is the
default STL.

Bug: 15193147
Change-Id: Ief6f539de36f38d38bd1460b17efcdc09114d64d
diff --git a/tests/Android.mk b/tests/Android.mk
index c9e1d26..45987f3 100644
--- a/tests/Android.mk
+++ b/tests/Android.mk
@@ -19,8 +19,6 @@
 
 LOCAL_STATIC_LIBRARIES := \
     libscrypt_static \
-    libgtest \
-    libgtest_main
 
 LOCAL_MODULE := scrypt_test