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/versionbits.cpp

@@ -111,7 +111,7 @@ void initialize()
 
 constexpr uint32_t MAX_START_TIME = 4102444800; // 2100-01-01
 
-FUZZ_TARGET_INIT(versionbits, initialize)
+FUZZ_TARGET(versionbits, .init = initialize)
 {
     const CChainParams& params = *g_params;
     const int64_t interval = params.GetConsensus().nPowTargetSpacing;