Temporary disable DL_WARNs for unused DT_*

Bug: 17552334
Bug: 18186310

(cherry picked from commit 1b77423eff21e916186fcb208f138e436e9f3052)

Change-Id: I8a9d05195a862bc287fff7156913606f0311b8bb
diff --git a/linker/linker.cpp b/linker/linker.cpp
index f8974eb..c3178cb 100644
--- a/linker/linker.cpp
+++ b/linker/linker.cpp
@@ -2069,7 +2069,7 @@
 
       default:
         if (!relocating_linker) {
-          DL_WARN("%s: unused DT entry: type %p arg %p", name,
+          DEBUG("%s: unused DT entry: type %p arg %p", name,
               reinterpret_cast<void*>(d->d_tag), reinterpret_cast<void*>(d->d_un.d_val));
         }
         break;