Fix John's nits

packages/contracts-bedrock/contracts/L1/OptimismPortal.sol

@@ -197,7 +197,7 @@ contract OptimismPortal is Initializable, ResourceMetering, Semver {
             provenWithdrawal.timestamp == 0 ||
                 (_l2BlockNumber == provenWithdrawal.l2BlockNumber &&
                     outputRoot != provenWithdrawal.outputRoot),
-            "OptimismPortal: withdrawalHash has already been proven"
+            "OptimismPortal: withdrawal hash has already been proven"
         );
 
         // Verify that the hash of this withdrawal was stored in the L2toL1MessagePasser contract on
@@ -214,7 +214,7 @@ contract OptimismPortal is Initializable, ResourceMetering, Semver {
 
         // Designate the withdrawalHash as proven by storing the `outputRoot`, `timestamp`,
         // and `l2BlockNumber` in the `provenWithdrawals` mapping. A withdrawalHash can only
-        // be proven one time to prevent a censorship attack unless it is submitted again
+        // be proven once to prevent a censorship attack unless it is submitted again
         // with a different outputRoot.
         provenWithdrawals[withdrawalHash] = ProvenWithdrawal({
             outputRoot: outputRoot,

packages/contracts-bedrock/contracts/test/OptimismPortal.t.sol

@@ -383,7 +383,7 @@ contract OptimismPortal_FinalizeWithdrawal_Test is Portal_Initializer {
             _withdrawalProof
         );
 
-        vm.expectRevert("OptimismPortal: withdrawalHash has already been proven");
+        vm.expectRevert("OptimismPortal: withdrawal hash has already been proven");
         op.proveWithdrawalTransaction(
             _defaultTx,
             _proposedBlockNumber,