[client] Add a note that only FAST_HASH is supported in Bloom filter …

…predicate

Add explicit note that only FAST_HASH is supported in the Bloom filter
predicate in client API.

There is already validation in BlockBloomFilter for hash algorithm.

Test:
- Verified the generated HTML output.

Change-Id: I5c683fe3be3e9ad2168562c5940e500fffac5316
Reviewed-on: http://gerrit.cloudera.org:8080/15608
Tested-by: Kudu Jenkins
Reviewed-by: Adar Dembo <[email protected]>

src/kudu/client/scan_predicate.h

@@ -144,6 +144,7 @@ class KUDU_EXPORT KuduBloomFilterBuilder {
   /// @param [in] hash_algorithm
   ///   Hash algorithm used to hash keys before inserting to the Bloom filter.
   ///   If not provided, defaults to FAST_HASH.
+  /// @note Currently only FAST_HASH is supported.
   /// @return Reference to the updated object.
   KuduBloomFilterBuilder& hash_algorithm(HashAlgorithm hash_algorithm);