[mingw-w64:bugs] #589 Compilation errors in multimon.h

Rename osvi argument to oi in IsPlatformNT().

Reported and patch by tobbez.
Signed-off-by: Jonathan Yong <10walls@gmail.com>

mingw-w64-headers/include/multimon.h

diff --git a/mingw-w64-headers/include/multimon.h b/mingw-w64-headers/include/multimon.h
index 1aefb10..3ea9ee1 100644
--- a/mingw-w64-headers/include/multimon.h
+++ b/mingw-w64-headers/include/multimon.h
@@ -127,7 +127,7 @@
   WINBOOL IsPlatformNT() {
     OSVERSIONINFOA oi = { 0 };
 
-    oi.dwOSVersionInfoSize = sizeof (osvi);
+    oi.dwOSVersionInfoSize = sizeof (oi);
     GetVersionExA ((OSVERSIONINFOA *) &oi);
     return (oi.dwPlatformId == VER_PLATFORM_WIN32_NT);
   }