fd-util: rename CLOSE_AND_REPLACE() -> close_and_replace()

We have free_and_replace() and friends, they are all named with lower
letters, even they are macros, not functions.
For consistency, let's rename CLOSE_AND_REPLACE() with lower letters.

This also mekes the macro used more places.

src/basic/fd-util.c

@@ -654,7 +654,7 @@ int rearrange_stdio(int original_input_fd, int original_output_fd, int original_
                                 goto finish;
                         }
 
-                        CLOSE_AND_REPLACE(null_fd, copy);
+                        close_and_replace(null_fd, copy);
                 }
         }