sysfs: fix warning when creating a sysfs group without attributes

When attempting to create a gropu without attrs, the warning prints the
name of the group.  However, the check for name being a NULL pointer is
wrong: it uses the pointer to the name when it's NULL.  Fix it to use
the name if present, otherwise just put an empty string.

Cc: Bruno Prémont <bonbons@linux-vserver.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Javi Merino <javi.merino@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fs/sysfs/group.c

@@ -99,7 +99,7 @@ static int internal_create_group(struct kobject *kobj, int update,
 		return -EINVAL;
 	if (!grp->attrs && !grp->bin_attrs) {
 		WARN(1, "sysfs: (bin_)attrs not set by subsystem for group: %s/%s\n",
-			kobj->name, grp->name ? "" : grp->name);
+			kobj->name, grp->name ?: "");
 		return -EINVAL;
 	}
 	if (grp->name) {