[NFC][SemaHLSL] Fix typo causing float to double conversion (#148941)

- it was noted,
[here](#145795 (comment)),
that by accidently not specifying this explicitly as a float it will
cause a build warning on MSVC

- this commit resolves this by explicitly specifying it as a float

Author: inbelic

clang/lib/Sema/SemaHLSL.cpp

@@ -1150,7 +1150,7 @@ bool SemaHLSL::handleRootSignatureElements(
       if (!llvm::hlsl::rootsig::verifyMaxAnisotropy(Sampler->MaxAnisotropy))
         ReportError(Loc, 0, 16);
       if (!llvm::hlsl::rootsig::verifyMipLODBias(Sampler->MipLODBias))
-        ReportFloatError(Loc, -16.f, 15.99);
+        ReportFloatError(Loc, -16.f, 15.99f);
     } else if (const auto *Clause =
                    std::get_if<llvm::hlsl::rootsig::DescriptorTableClause>(
                        &Elem)) {