Polish the signature of CallApplicationMain in klr

[troydai]

Here's the function pointer declaration (https://github.com/aspnet/KRuntime/blob/dev/src/klr/klr.h#L11)

typedef struct CALL_APPLICATION_MAIN_DATA
{
    LPCWSTR applicationBase; // application base of managed domain
    LPCWSTR klrDirectory; // path to KLR helper directory
    int argc; // Number of args in argv
    LPCWSTR* argv; // Array of arguments
    int exitcode; // Exit code from Managed Application
} *PCALL_APPLICATION_MAIN_DATA;

typedef HRESULT (STDAPICALLTYPE *FnCallApplicationMain)(
    PCALL_APPLICATION_MAIN_DATA pCallApplicationMainData
    );

The pCallApplicationMainData will contain the exit code, there is no need to return the it from the method again. The return type can be instead change to bool so that the caller can be further simplified.

[troydai]

@glennc @muratg If we're not going to fix it, should we just close it?

[muratg]

@davidfowl @lodejard What are your thoughts on this one?

[davidfowl]

Part of any clean up that @moozzyk does

[moozzyk]

The HRESULT returned by the FnCallApplicationMain does not represent the return value of the target function but the result of the operation of calling the target function (e.g. if for whatever reason we cannot start CoreClr the FnCallApplicationMain will return the HRESULT representing the failure and will not set the exitCode).

What we should probably fix is actually to remove this line:
https://github.com/aspnet/dnx/blob/dev/src/dnx.clr/dnx.clr.cpp#L30

[moozzyk]

Fixed in #2857