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

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: 84c45d5f3b ("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>

drivers/staging/gasket/gasket_sysfs.c

@@ -228,8 +228,7 @@ int gasket_sysfs_create_entries(struct device *device,
 	}
 
 	mutex_lock(&mapping->mutex);
-	for (i = 0; strcmp(attrs[i].attr.attr.name, GASKET_ARRAY_END_MARKER);
-		i++) {
+	for (i = 0; attrs[i].attr.attr.name != NULL; i++) {
 		if (mapping->attribute_count == GASKET_SYSFS_MAX_NODES) {
 			dev_err(device,
 				"Maximum number of sysfs nodes reached for device\n");

drivers/staging/gasket/gasket_sysfs.h

@@ -30,10 +30,6 @@
  */
 #define GASKET_SYSFS_MAX_NODES 196
 
-/* End markers for sysfs struct arrays. */
-#define GASKET_ARRAY_END_TOKEN GASKET_RESERVED_ARRAY_END
-#define GASKET_ARRAY_END_MARKER __stringify(GASKET_ARRAY_END_TOKEN)
-
 /*
  * Terminator struct for a gasket_sysfs_attr array. Must be at the end of
  * all gasket_sysfs_attribute arrays.