Update src/stdlib_math.fypp

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

Author: ejovo13

src/stdlib_math.fypp

@@ -61,7 +61,7 @@ module stdlib_math
     !! Create rank 1 array of linearly spaced elements from start to end.
     !! If the number of elements is not specified, create an array with size 100. If n is a negative value,
     !! return an array with size 0. If n = 1, return a rank 1 array whose only element is end. When dealing with integers as the `start` and `end`
-    !! parameters, the return type is always a double precision real.
+    !! parameters, the return type is always a `real(dp)`.
     !!
     !!([Specification](../page/specs/stdlib_math.html#linspace))
     #:for k1, t1 in INT_KINDS_TYPES