[VFS] Fix unused variable warning. NFC

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@351069 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Support/VirtualFileSystem.cpp

@@ -243,7 +243,7 @@ public:
       SmallString<128> PWD, RealPWD;
       if (llvm::sys::fs::current_path(PWD))
         return; // Awful, but nothing to do here.
-      if (auto Err = llvm::sys::fs::real_path(PWD, RealPWD))
+      if (llvm::sys::fs::real_path(PWD, RealPWD))
         WD = {PWD, PWD};
       else
         WD = {PWD, RealPWD};