Fixes these warnings:
C:\GitLab-Runner\builds\magjac\graphviz\cmd\lneato\mswin32\lneato.c(27,28): warning C4028: formal parameter 1 different from declaration [C:\GitLab-Runner\builds\magjac\graphviz\cmd\lneato\lneato.vcxproj]
C:\GitLab-Runner\builds\magjac\graphviz\cmd\lneato\mswin32\lneato.c(27,46): warning C4028: formal parameter 2 different from declaration [C:\GitLab-Runner\builds\magjac\graphviz\cmd\lneato\lneato.vcxproj]
See
https://docs.microsoft.com/en-us/windows/win32/api/winbase/nf-winbase-winmain.
static char *buildpath (char *);
static void panic (char *, int, char *, char *, ...);
-int WINAPI WinMain (HANDLE hInstance, HANDLE hPrevInstance,
+int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
LPSTR lpCmdLine, int nCmdShow) {
HANDLE handle;
char cmd[256];