Add missing libdl in linker option.

Change-Id: I5df90dc41d2b2c175e6c5ec0afeb97c4aa83bb89
diff --git a/tc/Android.mk b/tc/Android.mk
index 4a63875..86dbc97 100644
--- a/tc/Android.mk
+++ b/tc/Android.mk
@@ -8,7 +8,7 @@
 LOCAL_MODULE := tc
 
 LOCAL_SYSTEM_SHARED_LIBRARIES := \
-	libc libm
+	libc libm libdl
 
 LOCAL_SHARED_LIBRARIES += libiprouteutil libnetlink