staging: gasket: Remove stale pointers on error allocating attr array

If gasket_sysfs_create_mapping() hits errors allocating the attribute
array, remove stale pointers to device info from the mapping object.

Signed-off-by: Zhongze Hu <frankhu@chromium.org>
Signed-off-by: Todd Poynor <toddpoynor@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/gasket/gasket_sysfs.c

@@ -225,6 +225,8 @@ int gasket_sysfs_create_mapping(
 	mapping->attribute_count = 0;
 	if (!mapping->attributes) {
 		gasket_nodev_error("Unable to allocate sysfs attribute array.");
+		mapping->device = NULL;
+		mapping->gasket_dev = NULL;
 		mutex_unlock(&mapping->mutex);
 		mutex_unlock(&function_mutex);
 		return -ENOMEM;