Use the new name for the libc++ libbacktrace.

I'm removing the stlport flavored libbacktrace, so the libc++ one can
have the normal name now.

Bug: 15193147
Change-Id: Ie138bc8034533cae56ea15095eebc5f52e56f32d
diff --git a/runtime/Android.mk b/runtime/Android.mk
index 4505b8e..082e8dd 100644
--- a/runtime/Android.mk
+++ b/runtime/Android.mk
@@ -465,7 +465,7 @@
 
   LOCAL_SHARED_LIBRARIES := libnativehelper libnativebridge libsigchain
   include external/libcxx/libcxx.mk
-  LOCAL_SHARED_LIBRARIES += libbacktrace_libc++
+  LOCAL_SHARED_LIBRARIES += libbacktrace
   ifeq ($$(art_target_or_host),target)
     LOCAL_SHARED_LIBRARIES += libdl
     # ZipArchive support, the order matters here to get all symbols.