Fix a couple of dead links on core::num::ParseFloatError docs

Author: ollie27

src/libcore/num/dec2flt/mod.rs

@@ -154,8 +154,8 @@ from_str_float_impl!(f64);
 /// for [`f32`] and [`f64`].
 ///
 /// [`FromStr`]: ../str/trait.FromStr.html
-/// [`f32`]: ../primitive.f32.html
-/// [`f64`]: ../primitive.f64.html
+/// [`f32`]: ../../std/primitive.f32.html
+/// [`f64`]: ../../std/primitive.f64.html
 #[derive(Debug, Clone, PartialEq)]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct ParseFloatError {