assert can cause -Werror=implicit-function-declaration when NDEBUG is enabled

The NuttX assert implementation is as follows when NDEBUG is defined
https://github.com/apache/nuttx/blob/61a46ad39ef215213cb831d5b58834bf2a5a7ad0/include/assert.h#L103

Which can cause a `-Werror=implicit-function-declaration` when code assertion checks like this

```
#ifndef NDEBUG
static inline bool isokay(bool okay)
{
return okay
}
#endif

void foo()
{
assert(isokay(1))
}
```

When `NDEBUG` is defined the function `isokay` doesn't get declared but the assertion stills refers to it. Causing a `-Werror=implicit-function-declaration` error.
It seems that other implementations of assert() when NDEBUG is as follows
```
# define assert(f) ((void)(1))
```
Avoiding the `-Werror=implicit-function-declaration` error.