Update stdlib_math.fypp

Co-authored-by: Jeremie Vandenplas <jeremie.vandenplas@gmail.com>

Author: MilanSkocic

src/stdlib_math.fypp

@@ -481,7 +481,7 @@ contains
 
  end function deg2rad_${k1}$
 
- elemental function rad2deg_${k1}$(theta)result(result)
+ elemental function rad2deg_${k1}$(theta) result(result)
  ${t1}$, intent(in) :: theta
  ${t1}$ :: result
  result = theta * 180.0_${k1}$ / PI_${k1}$