Fix typo in PrintfConversionSpecifier::isDoubleArg()

This makes the printf diagnostics issue warnigns for %a, %A, %e, etc.
when used with the wrong argument.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@150370 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed