hecubafb: add module_put on error path in hecubafb_probe()

In hecubafb_probe(), after a successful try_module_get, vzalloc may
fail and make the hecubafb_probe return, but the module is not put on
this error path.

This patch adds an exit point that calls module_put in such situation.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Pavel Shved <shved@ispras.ru>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

drivers/video/hecubafb.c

@@ -233,7 +233,7 @@ static int __devinit hecubafb_probe(struct platform_device *dev)
 
 	videomemory = vzalloc(videomemorysize);
 	if (!videomemory)
-		return retval;
+		goto err_videomem_alloc;
 
 	info = framebuffer_alloc(sizeof(struct hecubafb_par), &dev->dev);
 	if (!info)
@@ -275,6 +275,7 @@ err_fbreg:
 	framebuffer_release(info);
 err_fballoc:
 	vfree(videomemory);
+err_videomem_alloc:
 	module_put(board->owner);
 	return retval;
 }