lntest+itest: update block height in MineBlockWithTx

Make sure we update the harness's current height and assert nodes have
been synced. Also fixes some typo found.

itest/lnd_multi-hop_force_close_test.go

@@ -2570,7 +2570,7 @@ func runLocalPreimageClaimLeased(ht *lntest.HarnessTest,
 	// We'll now mine enough blocks so Carol decides that she needs to go
 	// on-chain to claim the HTLC as Bob has been inactive.
 	numBlocks := padCLTV(
-		invoiceExpiry - ht.CurrentHeight() - incomingBroadcastDelta - 1,
+		invoiceExpiry - ht.CurrentHeight() - incomingBroadcastDelta,
 	)
 	ht.MineBlocks(int(numBlocks))
 

itest/lnd_sweep_test.go

@@ -1957,7 +1957,7 @@ func runBumpFee(ht *lntest.HarnessTest, alice *node.HarnessNode) {
 	// initial broadcast always succeeds.
 	assertFeeRateGreater(testFeeRate)
 
-	// Clean up the mempol.
+	// Clean up the mempool.
 	ht.MineBlocksAndAssertNumTxes(1, 2)
 }
 
@@ -2373,6 +2373,6 @@ func testFeeReplacement(ht *lntest.HarnessTest) {
 		uint64(feeRate), 0.02, "want %d, got %d in tx=%v",
 		currentFeeRate, feeRate, outgoingSweep2.TxHash())
 
-	// Finally, clean the mempol.
+	// Finally, clean the mempool.
 	ht.MineBlocksAndAssertNumTxes(1, 1)
 }