tracing/user_events: Use WRITE instead of READ for io vector import

import_single_range expects the direction/rw to be where it came from,
not the protection/limit. Since the import is in a write path use WRITE.

Link: https://lkml.kernel.org/r/[e-mail]
Link: https://lore.kernel.org/all/[e-mail]/

Reported-by: Mathieu Desnoyers <[e-mail]>
Signed-off-by: Beau Belgrave <[e-mail]>
Signed-off-by: Steven Rostedt (Google) <[e-mail]>

kernel/trace/trace_events_user.c

···
 	if (unlikely(*ppos != 0))
 		return -EFAULT;
 
-	if (unlikely(import_single_range(READ, (char *)ubuf, count, &iov, &i)))
+	if (unlikely(import_single_range(WRITE, (char __user *)ubuf,
+					 count, &iov, &i)))
 		return -EFAULT;
 
 	return user_events_write_core(file, &i);