Fix an uninitialized variable warning for g++ 12.2.0 (#10995)

Summary:
/home/wl/rocksdbtry/rocksdb-WL/util/bloom_test.cc: In constructor ‘rocksdb::RawFilterTester::RawFilterTester()’:
/home/wl/rocksdbtry/rocksdb-WL/util/bloom_test.cc:813:40: error: member ‘rocksdb::RawFilterTester::data_’ is used uninitialized [-Werror=uninitialized]

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10995

Reviewed By: cbi42

Differential Revision: D41620186

Pulled By: ajkr

fbshipit-source-id: a6ebd3820ef12e0af322cbfb7eb553de5bdfcb29

util/bloom_test.cc

@@ -806,7 +806,7 @@ TEST_P(FullBloomTest, Schema) {
 struct RawFilterTester {
   // Buffer, from which we always return a tail Slice, so the
   // last five bytes are always the metadata bytes.
-  std::array<char, 3000> data_;
+  std::array<char, 3000> data_{};
   // Points five bytes from the end
   char* metadata_ptr_;