multi: Fix a few typos.

blockchain/validate.go

@@ -4027,10 +4027,10 @@ func (b *BlockChain) checkConnectBlock(node *blockNode, block, parent *dcrutil.B
 	// earlier in the block which will typically not already be available in the
 	// view for the caller until after this function returns.  That means the
 	// caller would have to perform duplicate work that this function already
-	// performs to be able to create the filter.  Since the filter is is needed
-	// at this point to verify the header commitments, a good option is to
-	// simply create it here and allow the caller to request the filter be
-	// returned to it.
+	// performs to be able to create the filter.  Since the filter is needed at
+	// this point to verify the header commitments, a good option is to simply
+	// create it here and allow the caller to request the filter be returned to
+	// it.
 	filter, err := blockcf2.Regular(block.MsgBlock(), view)
 	if err != nil {
 		return ruleError(ErrMissingTxOut, err.Error())

dcrec/secp256k1/ecdsa/signature.go

@@ -822,7 +822,7 @@ func RecoverCompact(signature, hash []byte) (*secp256k1.PublicKey, bool, error)
 	// The method described by section 4.1.6 of [SEC1] to determine which one is
 	// the correct one involves calculating each possibility as a candidate
 	// public key and comparing the candidate to the authentic public key.  It
-	// also hints that is is possible to generate the signature in a such a
+	// also hints that it is possible to generate the signature in a such a
 	// way that only one of the candidate public keys is viable.
 	//
 	// A more efficient approach that is specific to the secp256k1 curve is used

dcrec/secp256k1/schnorr/signature_test.go

@@ -265,7 +265,7 @@ func TestSchnorrSignAndVerify(t *testing.T) {
 		// Ensure the test data is sane by comparing the provided hashed message
 		// and nonce, in the case rfc6979 was used, to their calculated values.
 		// These values could just be calculated instead of specified in the
-		// test data, but it's nice to have all of the calcuated values
+		// test data, but it's nice to have all of the calculated values
 		// available in the test data for cross implementation testing and
 		// verification.
 		calcHash := blake256.Sum256(msg)