Merge pull request #1042 from herbie-fp/zane-fix-extra-variable-in-benchmark

Remove extra variable y.

Author: pavpanchekha

bench/mathematics/logistic-regression.fpcore

@@ -10,6 +10,6 @@
 
  (- (log (+ 1 (exp x))) (* x y)))
 
-(FPCore (x y)
+(FPCore (x)
  :name "Logistic function from Lakshay Garg"
  (- (/ 2 (+ 1 (exp (* -2 x)))) 1))