patch 8.2.4256: MS-Windows: compiler warnings when compiled with /W4

Problem:    MS-Windows: compiler warnings when compiled with /W4.
Solution:   Small adjustments to the code. (Ken Takata, closes #9659)
diff --git a/src/gui_w32.c b/src/gui_w32.c
index 4a8917f..11ab234 100644
--- a/src/gui_w32.c
+++ b/src/gui_w32.c
@@ -5780,7 +5780,7 @@
  * noticeably so.
  */
     static void
-RevOut( HDC s_hdc,
+RevOut( HDC hdc,
 	int col,
 	int row,
 	UINT foptions,
@@ -5792,7 +5792,7 @@
     int		ix;
 
     for (ix = 0; ix < (int)len; ++ix)
-	ExtTextOut(s_hdc, col + TEXT_X(ix), row, foptions,
+	ExtTextOut(hdc, col + TEXT_X(ix), row, foptions,
 					pcliprect, text + ix, 1, padding);
 }
 #endif
@@ -5868,7 +5868,6 @@
 {
     static int	*padding = NULL;
     static int	pad_size = 0;
-    int		i;
     const RECT	*pcliprect = NULL;
     UINT	foptions = 0;
     static WCHAR *unicodebuf = NULL;
@@ -5959,6 +5958,8 @@
 
     if (pad_size != Columns || padding == NULL || padding[0] != gui.char_width)
     {
+	int	i;
+
 	vim_free(padding);
 	pad_size = Columns;