Use empty() member functions when that's what's being tested for instead
of comparing begin() and end().

llvm-svn: 42585
diff --git a/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp b/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
index b561c04..9ff41ca 100644
--- a/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
+++ b/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
@@ -1053,7 +1053,7 @@
   O << "\n";
 
   // Output stubs for external and common global variables.
-  if (GVStubs.begin() != GVStubs.end()) {
+  if (!GVStubs.empty()) {
     SwitchToDataSection(".non_lazy_symbol_pointer");
     for (std::set<std::string>::iterator I = GVStubs.begin(),
          E = GVStubs.end(); I != E; ++I) {