misc: fix error formatting in multiple files

lnwallet/channel.go

@@ -3920,7 +3920,7 @@ func genHtlcSigValidationJobs(localCommitmentView *commitment,
 			// Make sure there are more signatures left.
 			if i >= len(htlcSigs) {
 				return nil, fmt.Errorf("not enough HTLC " +
-					"signatures.")
+					"signatures")
 			}
 
 			// With the sighash generated, we'll also store the
@@ -3974,7 +3974,7 @@ func genHtlcSigValidationJobs(localCommitmentView *commitment,
 			// Make sure there are more signatures left.
 			if i >= len(htlcSigs) {
 				return nil, fmt.Errorf("not enough HTLC " +
-					"signatures.")
+					"signatures")
 			}
 
 			// With the sighash generated, we'll also store the