Updated function signature.

OnDeleteItem function signature should have an int as it's first parameter.

Author: isaac868

docs/mfc/reference/wm-message-handlers-d-e.md

@@ -12,7 +12,7 @@ The following map entries on the left correspond to the function prototypes on t
 |Map entry|Function prototype|
 |---------------|------------------------|
 |ON_WM_DEADCHAR()|afx_msg void [OnDeadChar](../../mfc/reference/cwnd-class.md#ondeadchar)(UINT, UINT, UINT);|
-|ON_WM_DELETEITEM()|afx_msg void [OnDeleteItem](../../mfc/reference/cwnd-class.md#ondeleteitem)(LPDELETEITEMSTRUCT);|
+|ON_WM_DELETEITEM()|afx_msg void [OnDeleteItem](../../mfc/reference/cwnd-class.md#ondeleteitem)(int, LPDELETEITEMSTRUCT);|
 |ON_WM_DESTROY()|afx_msg void [OnDestroy](../../mfc/reference/cwnd-class.md#ondestroy)();|
 |ON_WM_DESTROYCLIPBOARD()|afx_msg void [OnDestroyClipboard](../../mfc/reference/cwnd-class.md#ondestroyclipboard)();|
 |ON_WM_DEVICECHANGE()|afx_msg void [OnDeviceChange](../../mfc/reference/cwnd-class.md#ondevicechange)(UINT, DWORD);|