staging: gasket: Fix incongruency in handling of sysfs entries creation

staging: gasket: Fix incongruency in handling of sysfs entries creation

commit 9195d762042b0e5e4ded63606b4b30a93cba4400 upstream.

Fix incongruency in handling of sysfs entries creation.
This issue could cause invalid memory accesses, by not properly
detecting the end of the sysfs attributes array.

Fixes: 84c45d5f3bf1 ("staging: gasket: Replace macro __ATTR with __ATTR_NULL")
Signed-off-by: Luis Mendes <luis.p.mendes@gmail.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200403151534.20753-1-luis.p.mendes@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>