* numeric.c: Fix rdoc for Fixnum#**

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39062 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

numeric.c

@@ -2939,7 +2939,7 @@ int_pow(long x, unsigned long y)
  *  be negative or fractional.
  *
  *    2 ** 3      #=> 8
- *    2 ** -1     #=> 0.5
+ *    2 ** -1     #=> (1/2)
  *    2 ** 0.5    #=> 1.4142135623731
  */