The function framebuffer_release just calls kfree, so calling kfree
subsequently on the same argument represents a double free. The comments with
the definition of framebuffer_release in drivers/video/fbsysfs.c suggest that
a more elaborate definition of this function is planned, such that the
splitting up of framebuffer_release and kfree as done in the second instance
might someday make sense, but it does not make sense now.
This was found using the following semantic match.
(http://www.emn.fr/x-info/coccinelle/)