user32: Turn magic values into static constants.

dlls/user32/button.c

@@ -201,7 +201,7 @@ static inline void paint_button( HWND hwnd, LONG style, UINT action )
 /* retrieve the button text; returned buffer must be freed by caller */
 static inline WCHAR *get_button_text( HWND hwnd )
 {
-    INT len = 512;
+    static const INT len = 512;
     WCHAR *buffer = HeapAlloc( GetProcessHeap(), 0, (len + 1) * sizeof(WCHAR) );
     if (buffer) InternalGetWindowText( hwnd, buffer, len + 1 );
     return buffer;

dlls/user32/edit.c

@@ -2883,7 +2883,7 @@ static void EDIT_EM_SetLimitText(EDITSTATE *es, UINT limit)
  */
 static int calc_min_set_margin_size(HDC dc, INT left, INT right)
 {
-    WCHAR magic_string[] = {'\'','*','*','\'', 0};
+    static const WCHAR magic_string[] = {'\'','*','*','\'', 0};
     SIZE sz;
 
     GetTextExtentPointW(dc, magic_string, sizeof(magic_string)/sizeof(WCHAR) - 1, &sz);