[mlir/quant] fix a small typo in the quant utility

[liufengdb]

Summary

This is an edge case where the input type is a primitive type.

mlir/lib/Dialect/Quant/Utils/UniformSupport.cpp

ExpressedToQuantizedConverter::forInputType(Type inputType) {
   }
 }
 
 Type ExpressedToQuantizedConverter::convert(QuantizedType elementalType) const {
   assert(expressedType && "convert() on unsupported conversion");
 
   switch (inputType.getKind()) {
   default:
-    if (isQuantizablePrimitiveType(elementalType)) {
-      // For primitives, just use the new elemental type.
+    if (elementalType.getExpressedType() == expressedType) {
+      // If the expressed types match, just use the new elemental type.
       return elementalType;
     }
     // Unsupported.
     return nullptr;
   case StandardTypes::RankedTensor:
     return RankedTensorType::get(inputType.cast<RankedTensorType>().getShape(),
                                  elementalType);
   case StandardTypes::UnrankedTensor: