Bionic tests require libdl.so

Change-Id: I10c034acd99b0f494d6fe4b49f43272764c58f90
diff --git a/tests/tests/bionic/Android.mk b/tests/tests/bionic/Android.mk
index f81bcd9..088b9f7 100644
--- a/tests/tests/bionic/Android.mk
+++ b/tests/tests/bionic/Android.mk
@@ -44,7 +44,7 @@
     main.cpp \
 
 LOCAL_LDLIBS += \
-    -lrt \
+    -lrt -ldl \
 
 LOCAL_WHOLE_STATIC_LIBRARIES += \
     libBionicTests \