Remove needless 0 check.

galois.go

@@ -62,8 +62,7 @@ var logTable = [fieldSize]byte{
 
 /**
  * Inverse of the logarithm table.  Maps integer logarithms
- * to members of the field.  There is no entry for 255
- * because the highest log is 254.
+ * to members of the field.  Entry 255 is the same as entry 0 sue to mod 255.
  *
  * This table was generated by `go run gentables.go`
  * Table has been truncated to 256 bytes, since no lookups are bigger.
@@ -892,10 +891,7 @@ func galOneOver(a byte) byte {
 	if a == 0 {
 		panic("Argument 'divisor' is 0")
 	}
-	logResult := logTable[a]
-	if logResult != 0 {
-		logResult ^= 255
-	}
+	logResult := logTable[a] ^ 255
 	return expTable[logResult]
 }