Simplify. No functionality change.

llvm-svn: 195051
diff --git a/lld/lib/Core/SymbolTable.cpp b/lld/lib/Core/SymbolTable.cpp
index c0405dd..a8f5250 100644
--- a/lld/lib/Core/SymbolTable.cpp
+++ b/lld/lib/Core/SymbolTable.cpp
@@ -317,9 +317,7 @@
   const Atom *atom = this->findByName(sym);
   if (atom == nullptr)
     return false;
-  if (atom->definition() == Atom::definitionUndefined)
-    return false;
-  return true;
+  return atom->definition() != Atom::definitionUndefined;
 }
 
 void SymbolTable::addReplacement(const Atom *replaced,