Remove unused LOCAL_LDLIBS.

Change-Id: I42aeb7668183e7a06207ee063f6eee4d37d66c6e
diff --git a/libbacktrace/Android.mk b/libbacktrace/Android.mk
index a7305da..7fe52ef 100755
--- a/libbacktrace/Android.mk
+++ b/libbacktrace/Android.mk
@@ -105,10 +105,8 @@
 	GetPss.cpp \
 	thread_utils.c \
 
-backtrace_test_ldlibs := \
-	-lpthread \
-
 backtrace_test_ldlibs_host := \
+	-lpthread \
 	-lrt \
 
 backtrace_test_shared_libraries := \