headers: kobject.h redux

Remove kobject.h from files which don't need it, notably,
sched.h and fs.h.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/sysfs/sysfs.h

@@ -9,6 +9,7 @@
  */
 
 #include <linux/lockdep.h>
+#include <linux/kobject_ns.h>
 #include <linux/fs.h>
 
 struct sysfs_open_dirent;