bpf: Remove unused including <linux/version.h>

Remove including <linux/version.h> that don't need it.
Signed-off-by: Tian Tao <tiantao6@hisilicon.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/1608086835-54523-1-git-send-email-tiantao6@hisilicon.com

kernel/bpf/syscall.c

@@ -17,7 +17,6 @@
 #include <linux/fs.h>
 #include <linux/license.h>
 #include <linux/filter.h>
-#include <linux/version.h>
 #include <linux/kernel.h>
 #include <linux/idr.h>
 #include <linux/cred.h>