bpf: remove duplicated include from syscall.c

Remove duplicated include.
Signed-off-by: NYueHaibing <yuehaibing@huawei.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

kernel/bpf/syscall.c

@@ -30,7 +30,6 @@
 #include <linux/cred.h>
 #include <linux/timekeeping.h>
 #include <linux/ctype.h>
-#include <linux/btf.h>
 #include <linux/nospec.h>
 
 #define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY || \