lneato: Windows: correct argument types to WinMain

lneato: Windows: correct argument types to WinMain

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.