[llvm-dwarfdump] - Attemp to fix BB after r310915.

Now MIPS one is unhappy:
http://lab.llvm.org:8011/builders/llvm-mips-linux/builds/2221

llvm-svn: 310928
diff --git a/llvm/lib/DebugInfo/DWARF/DWARFDie.cpp b/llvm/lib/DebugInfo/DWARF/DWARFDie.cpp
index 7086535..09c0044 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFDie.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFDie.cpp
@@ -77,7 +77,7 @@
 
     // Print section index if name is not unique.
     if (!SectionNames[R.SectionIndex].IsNameUnique)
-      OS << format(" [%u]", R.SectionIndex);
+      OS << format(" [%" PRIu64 "]", R.SectionIndex);
   }
 }