Avoid int to string conversion in Twine or raw_ostream contexts.

Some output changes from uppercase hex to lowercase hex, no other functionality change intended.

llvm-svn: 321526
diff --git a/llvm/lib/Support/ARMAttributeParser.cpp b/llvm/lib/Support/ARMAttributeParser.cpp
index 3d800eb..e39bddc 100644
--- a/llvm/lib/Support/ARMAttributeParser.cpp
+++ b/llvm/lib/Support/ARMAttributeParser.cpp
@@ -666,7 +666,7 @@
       ParseIndexList(Data, Offset, Indicies);
       break;
     default:
-      errs() << "unrecognised tag: 0x" << utohexstr(Tag) << '\n';
+      errs() << "unrecognised tag: 0x" << Twine::utohexstr(Tag) << '\n';
       return;
     }