Removed obsolete symbol cmsg_nxthdr.

Bug: 15822452
Change-Id: I5322fb29522fc58e9c3489ff86216e25a12ef970
diff --git a/libc/bionic/cmsg_nxthdr.cpp b/libc/bionic/cmsg_nxthdr.cpp
index 8a2b33e..f962788 100644
--- a/libc/bionic/cmsg_nxthdr.cpp
+++ b/libc/bionic/cmsg_nxthdr.cpp
@@ -37,6 +37,3 @@
   }
   return ptr;
 }
-
-// TODO: remove after NDK refresh.
-__weak_alias(cmsg_nxthdr, __cmsg_nxthdr);