patch 8.2.4289: warnings reported by MSVC

Problem:    Warnings reported by MSVC.
Solution:   Rename variables and other fixes. (Ken Takata, closes #9689)
diff --git a/src/os_win32.c b/src/os_win32.c
index 18b9e59..d2d2fe7 100644
--- a/src/os_win32.c
+++ b/src/os_win32.c
@@ -452,7 +452,7 @@
     HANDLE hHandle,
     DWORD dwMilliseconds)
 {
-    if (read_console_input(NULL, NULL, -2, NULL))
+    if (read_console_input(NULL, NULL, (DWORD)-2, NULL))
 	return WAIT_OBJECT_0;
     return WaitForSingleObject(hHandle, dwMilliseconds);
 }
@@ -724,7 +724,7 @@
     for (i = 0; libintl_entry[i].name != NULL
 					 && libintl_entry[i].ptr != NULL; ++i)
     {
-	if ((*libintl_entry[i].ptr = (FARPROC)GetProcAddress(hLibintlDLL,
+	if ((*libintl_entry[i].ptr = GetProcAddress(hLibintlDLL,
 					      libintl_entry[i].name)) == NULL)
 	{
 	    dyn_libintl_end();