sysfs: Mark sysfs_attr_ns static

Nothing outside of fs/sysfs/file.c references this function, so mark it static.
Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fs/sysfs/file.c

@@ -485,7 +485,7 @@ const struct file_operations sysfs_file_operations = {
 	.poll		= sysfs_poll,
 };
 
-int sysfs_attr_ns(struct kobject *kobj, const struct attribute *attr,
+static int sysfs_attr_ns(struct kobject *kobj, const struct attribute *attr,
 			 const void **pns)
 {
 	struct sysfs_dirent *dir_sd = kobj->sd;