drm/amd/display: handler not correctly checked at remove_irq_handler

[why]
handler is supposedly passed in as a function pointer;
however, the entire struct amdgpu_dm_irq_handler_data
gets from the list is used to check match.

[how]
use the interrupt_handler within amdgpu_dm_irq_handler_data
for checking match.

Signed-off-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Acked-by: Bindu Ramamurthy <bindu.r@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_irq.c

@@ -165,7 +165,10 @@ static struct list_head *remove_irq_handler(struct amdgpu_device *adev,
 		handler = list_entry(entry, struct amdgpu_dm_irq_handler_data,
 				     list);
 
-		if (ih == handler) {
+		if (handler == NULL)
+			continue;
+
+		if (ih == handler->handler) {
 			/* Found our handler. Remove it from the list. */
 			list_del(&handler->list);
 			handler_removed = true;