scripted-diff: Use new FUZZ_TARGET macro everywhere

-BEGIN VERIFY SCRIPT-

  ren() { sed --regexp-extended -i "s|$1|$2|g" $(git grep -l --extended-regexp "$1"); }

  # Replace FUZZ_TARGET_INIT
  ren 'FUZZ_TARGET_INIT\((.+), (.+)\)' 'FUZZ_TARGET(\1, .init = \2)'

  # Delete unused FUZZ_TARGET_INIT
  sed -i -e '37,39d' src/test/fuzz/fuzz.h

-END VERIFY SCRIPT-

src/test/fuzz/pow.cpp

@@ -23,7 +23,7 @@ void initialize_pow()
     SelectParams(ChainType::MAIN);
 }
 
-FUZZ_TARGET_INIT(pow, initialize_pow)
+FUZZ_TARGET(pow, .init = initialize_pow)
 {
     FuzzedDataProvider fuzzed_data_provider(buffer.data(), buffer.size());
     const Consensus::Params& consensus_params = Params().GetConsensus();
@@ -87,7 +87,7 @@ FUZZ_TARGET_INIT(pow, initialize_pow)
 }
 
 
-FUZZ_TARGET_INIT(pow_transition, initialize_pow)
+FUZZ_TARGET(pow_transition, .init = initialize_pow)
 {
     FuzzedDataProvider fuzzed_data_provider(buffer.data(), buffer.size());
     const Consensus::Params& consensus_params{Params().GetConsensus()};