[0.22] Initialize base params on FEC benchmarking

The FEC logic computes the memory-mapped FEC chunk storage filename
using gArgs.GetDataDirNet(). The latter, in turn, calls
ArgsManager::GetDataDir, which uses "BaseParams().DataDir()". But
BaseParams() needs globalChainBaseParams to be initialized, and that can
only hold if SelectParams() has been called before. This seems to be
required now, perhaps due to changes related to Bitcoin Core PR bitcoin#21005.

src/bench/fec.cpp

@@ -9,11 +9,11 @@
 #include "consensus/merkle.h"
 #include "fec.h"
 #include "random.h"
+#include "streams.h"
 #include "txmempool.h"
 #include "util/time.h"
-
-#include "streams.h"
 #include "version.h"
+#include <chainparams.h>
 
 #include <random>
 
@@ -274,6 +274,8 @@ static void FECEncodeAllBenchmark(benchmark::Bench& bench) { FECEncodeBenchmark(
 
 static void FECDecodeBenchmark(benchmark::Bench& bench, unsigned mask, const MemoryUsageMode memory_usage_mode)
 {
+    SelectParams(CBaseChainParams::REGTEST);
+
     const auto& data = benchmark::data::block413567;
     size_t fec_chunk_count = DIV_CEIL(data.size(), FEC_CHUNK_SIZE);
     std::pair<std::unique_ptr<FECChunkType[]>, std::vector<uint32_t>> fec(std::piecewise_construct, std::forward_as_tuple(new FECChunkType[fec_chunk_count]), std::forward_as_tuple(fec_chunk_count));