scripted-diff: Remove redundant sync_all and sync_blocks

The sync calls are redundant after a call to generate, because generate
already syncs itself.

-BEGIN VERIFY SCRIPT-
perl -0777 -pi -e 's/(generate[^\n]*\)[^\n]*)(\n|\s)+self.sync_(all|blocks)\([^\)]*\)\n/\1\n/g' $(git grep -l generate ./test)
-END VERIFY SCRIPT-

test/functional/wallet_txn_doublespend.py

@@ -124,7 +124,6 @@ class TxnMallTest(BitcoinTestFramework):
         # Reconnect the split network, and sync chain:
         self.connect_nodes(1, 2)
         self.generate(self.nodes[2], 1)  # Mine another block to make sure we sync
-        self.sync_blocks()
         assert_equal(self.nodes[0].gettransaction(doublespend_txid)["confirmations"], 2)
 
         # Re-fetch transaction info: