Compilation warnings regarding calc-math.el

[Eli Zaretskii]

FYI: Byte-compiling calc-math.el yields the following warnings:

  In calc-arctan:
  calc-math.el:239:8:Warning: function `calc-arctan' defined multiple times in
      this file

  In calc-tanh:
  calc-math.el:244:8:Warning: function `calc-tanh' defined multiple times in
      this file

  In calc-arctanh:
  calc-math.el:249:8:Warning: function `calc-arctanh' defined multiple times in
      this file

  In calcFunc-cot:
  calc-math.el:966:22:Warning: malformed let binding: `(and (equal na nb)
      (math-sort-intv (nth 1 x) (math-cot-raw (nth 2 xx)) (math-cot-raw (nth 3
      xx))))'