Fix invalid _float type for _fdpoly syntax in "Floating-point primitives" topic

Author: Rageking8

docs/c-runtime-library/reference/floating-point-primitives.md

@@ -235,7 +235,7 @@ These floating-point primitives normalize the fractional part of an underflowed
 ```C
 double __cdecl _dpoly(double x, double const* table, int n);
 long double __cdecl _ldpoly(long double x, long double const* table, int n);
-float __cdecl _fdpoly(float x, _float const* table, int n);
+float __cdecl _fdpoly(float x, float const* table, int n);
 ```
 
 ### Parameters