headers: remove sched.h from poll.h

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/select.c b/fs/select.c
index a201fc3..fd38ce2 100644
--- a/fs/select.c
+++ b/fs/select.c
@@ -15,6 +15,7 @@
  */
 
 #include <linux/kernel.h>
+#include <linux/sched.h>
 #include <linux/syscalls.h>
 #include <linux/module.h>
 #include <linux/slab.h>