Fix merge-induced makefile error.

Change-Id: I6ac7e5e3b9d55108681916044cf2de0e01bca0b2
diff --git a/tests/Android.mk b/tests/Android.mk
index f65d82b..9026762 100644
--- a/tests/Android.mk
+++ b/tests/Android.mk
@@ -235,7 +235,6 @@
     dlext_test.cpp \
     dlfcn_test.cpp \
     stack_unwinding_test.cpp \
-    stack_unwinding_test_impl.c \
 
 bionic-unit-tests_cflags := $(test_cflags)