Fix some lint issues in nuttx

[Acfboy]

Hi, @ghaerr . Could we fix some ci -Werror issue mentioned in apache/nuttx#19912 here?

• Guard the memplan4 framebuffer subdriver declaration with #if ELKS so it is not an unused variable on non-ELKS builds.
• Convert the space-indented statements in GdRasterOp to tabs to fix the misleading-indentation warning.
• Declare FARPROC, NEARPROC and PROC with (void) parameters to fix the strict-prototypes warning.

[ghaerr]

Could we fix some ci -Werror issue mentioned in apache/nuttx#19912 here?

Sure. I can see there's more warnings there than I would have thought. I may clean up some of the others seen when I have time.

Declare FARPROC, NEARPROC and PROC with (void) parameters to fix the strict-prototypes warning.

I don't see any actual uses of FARPROC or NEARPROC, but not fully sure about PROC. In some cases, adding a (void) parameter list could cause problems should their current empty () be required to allow a variety of arguments, but lets go ahead and change this now, as if this issue comes up it can always be changed back.

Thanks!

[ppisa]

As I mention in #194 (comment) , the relatively mild intrusive solution to undefined macros warning is use of the next pragma at start of header files and C files where it is necessary

#pragma GCC diagnostic ignored "-Wundef"

and I expect that large part would be solved by adding it at start of mwconfig.h or it can be put even to mwconfig.nuttx but I think that its use for all targets would be OK and advantage.

[ghaerr]

@ppisa,

#pragma GCC diagnostic ignored "-Wundef"

If this works for NuttX, that's great, lets add it.

it can be put even to mwconfig.nuttx

Since the problem only occurs with the NuttX configuration requiring -Wundef, I would prefer solving the problem using only mwconfig.nuttx, as it seems that the real issue here is that -Wundef is incompatible with the way that Microwindows uses symbols for #if directives. This leaves the rest of the compilations as-is, where no warnings are currently produced.

Please submit a PR if this sounds good.