tracing: Do not block on splice if either file or splice NONBLOCK flag is set

Currently only the splice NONBLOCK flag is checked to determine if
the splice read should block or not. But the file descriptor NONBLOCK
flag also needs to be checked.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

Author: rostedt

kernel/trace/trace.c

@@ -4593,7 +4593,7 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
 
 	/* did we read anything? */
 	if (!spd.nr_pages) {
-		if (flags & SPLICE_F_NONBLOCK)
+		if ((file->f_flags & O_NONBLOCK) || (flags & SPLICE_F_NONBLOCK))
 			ret = -EAGAIN;
 		else
 			ret = 0;