fix whitespace

Author: fsaadatmand

Diff for: chapter04/4-3.c

@@ -1,6 +1,7 @@
 /* 
  * Exercise 4-3. Given the basic framework, it's straightforward to extend the
  * calculator. Add the modulus (%) operator and provisions for negative numbers
+ *
  * By Faisal Saadatmand
  */