For some m68k configs, I get:

| net/rfkill/rfkill-input.c: In function 'rfkill_start':
| net/rfkill/rfkill-input.c:208: error: dereferencing pointer to incomplete type

As the incomplete type is `struct task_struct', including <linux/sched.h> fixes
it.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>