llvm-objdump.cpp: Appease MSC16 x64. utostr(n++) causes internal compiler error.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182722 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/llvm-objdump/llvm-objdump.cpp b/tools/llvm-objdump/llvm-objdump.cpp
index d8611d8..8049dac 100644
--- a/tools/llvm-objdump/llvm-objdump.cpp
+++ b/tools/llvm-objdump/llvm-objdump.cpp
@@ -355,8 +355,9 @@
                                        FI != FE; ++FI) {
       static int filenum = 0;
       emitDOTFile((Twine((*FI)->getName()) + "_" +
-                   utostr(filenum++) + ".dot").str().c_str(),
+                   utostr(filenum) + ".dot").str().c_str(),
                     **FI, IP.get());
+      ++filenum;
     }
   }