bpf: clean up put_cpu_var usage

put_cpu_var takes the percpu data, not the data returned from
get_cpu_var.

This doesn't change the behavior.

Cc: Tejun Heo <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Signed-off-by: Shaohua Li <[email protected]>
Acked-by: Alexei Starovoitov <[email protected]>
Acked-by: Tejun Heo <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

Author: shligit

kernel/bpf/core.c

@@ -1031,7 +1031,7 @@ BPF_CALL_0(bpf_user_rnd_u32)
 
 	state = &get_cpu_var(bpf_user_rnd_state);
 	res = prandom_u32_state(state);
-	put_cpu_var(state);
+	put_cpu_var(bpf_user_rnd_state);
 
 	return res;
 }