linker: make it less unclear that all the workarounds are ILP32-only.

I'll come back to improve the name of has_min_version(), but i'll need a good suggestion first!

Change-Id: I76ed620768b57b6eb23261627f2cb2ff539c184a
diff --git a/linker/dlfcn.cpp b/linker/dlfcn.cpp
index f811d6d..fc95903 100644
--- a/linker/dlfcn.cpp
+++ b/linker/dlfcn.cpp
@@ -345,7 +345,7 @@
     __libdl_info->soname_ = linker_si.soname_;
     __libdl_info->target_sdk_version_ = __ANDROID_API__;
     __libdl_info->generate_handle();
-#if defined(__work_around_b_24465209__)
+#if !defined(__LP64__)
     strlcpy(__libdl_info->old_name_, __libdl_info->soname_.c_str(),
             sizeof(__libdl_info->old_name_));
 #endif