[ELF] Simplify. NFC

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@352499 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/ELF/SymbolTable.cpp b/ELF/SymbolTable.cpp
index 8a55cd8..7a80124 100644
--- a/ELF/SymbolTable.cpp
+++ b/ELF/SymbolTable.cpp
@@ -326,7 +326,7 @@
 
     // We don't report backward references to weak symbols as they can be
     // overridden later.
-    if (Backref && S->Binding != STB_WEAK)
+    if (Backref && !S->isWeak())
       warn("backward reference detected: " + Name + " in " + toString(File) +
            " refers to " + toString(S->File));
   }