Revert r109428 "Hoist argument type checking into CheckFormatHandler. This is prep for scanf format"

Got errors about ASTContext being undefined with Visual Studio 2010.

llvm-svn: 109491

clang/lib/Analysis/ScanfFormatString.cpp

@@ -218,10 +218,4 @@ bool clang::analyze_format_string::ParseScanfString(FormatStringHandler &H,
   return false;
 }
 
-ArgTypeResult ScanfSpecifier::getArgType(ASTContext &Ctx) const {
-  // FIXME: Fill in.
-  return ArgTypeResult();
-}
-
-