docs: fix interpolation string

Signed-off-by: Athan <[email protected]>

Author: kgryte

lib/node_modules/@stdlib/math/base/special/factorial2f/README.md

@@ -177,7 +177,7 @@ int main( void ) {
     int i;
     for ( i = 0; i < 5; i++ ) {
         b = stdlib_base_factorial2f( x[ i ] );
-        printf ( "factorial2f(%lf) = %f\n", x[ i ], b );
+        printf ( "factorial2f(%f) = %f\n", x[ i ], b );
     }
 }
 ```