Fix HyperLogLog type registration in registerApproxDistinctAggregates (…

…facebookincubator#10664)

Summary:
Prefix is not needed to register custom type `HyperLogLog` in `ApproxDistinctAggregates`.
`registerHyperLogLogType` is used instead to make registration of customType `HyperLogLog`
uniform across velox.

Use of prefix in `registerCustomType` here resulted in the following error while running tests
in [presto PR](prestodb/presto#22332):
```
Reason: Type doesn't exist: 'HYPERLOGLOG'
Retriable: False
Function: validateBaseTypeAndCollectTypeParams
File: /Users/pramod/Desktop/velox/velox/expression/FunctionSignature.cpp
Line: 125
```

Pull Request resolved: facebookincubator#10664

Reviewed By: bikramSingh91

Differential Revision: D61163251

Pulled By: xiaoxmeng

fbshipit-source-id: 8d316a9bc863a779ab81a50fb06b5d3761d8316b

velox/functions/prestosql/aggregates/ApproxDistinctAggregate.cpp

@@ -523,9 +523,7 @@ void registerApproxDistinctAggregates(
     const std::string& prefix,
     bool withCompanionFunctions,
     bool overwrite) {
-  registerCustomType(
-      prefix + "hyperloglog",
-      std::make_unique<const HyperLogLogTypeFactories>());
+  registerHyperLogLogType();
   registerApproxDistinct(
       prefix + kApproxDistinct,
       false,