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/key.cpp

@@ -35,7 +35,7 @@ void initialize_key()
     SelectParams(ChainType::REGTEST);
 }
 
-FUZZ_TARGET_INIT(key, initialize_key)
+FUZZ_TARGET(key, .init = initialize_key)
 {
     const CKey key = [&] {
         CKey k;
@@ -308,7 +308,7 @@ FUZZ_TARGET_INIT(key, initialize_key)
     }
 }
 
-FUZZ_TARGET_INIT(ellswift_roundtrip, initialize_key)
+FUZZ_TARGET(ellswift_roundtrip, .init = initialize_key)
 {
     FuzzedDataProvider fdp{buffer.data(), buffer.size()};
 
@@ -327,7 +327,7 @@ FUZZ_TARGET_INIT(ellswift_roundtrip, initialize_key)
     assert(key.VerifyPubKey(decoded_pubkey));
 }
 
-FUZZ_TARGET_INIT(bip324_ecdh, initialize_key)
+FUZZ_TARGET(bip324_ecdh, .init = initialize_key)
 {
     FuzzedDataProvider fdp{buffer.data(), buffer.size()};