tracing: Remove unneeded NULL check

We checked "iter->trace" earlier so there is no need to check here.

Link: http://lkml.kernel.org/r/20141122183012.GB6994@mwandaSigned-off-by: Dan Carpenter <dan.carpenter@oracle.com>
[ Pulled from the archeological digging of my INBOX ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

kernel/trace/trace.c

@@ -4224,7 +4224,7 @@ __tracing_open(struct inode *inode, struct file *file, bool snapshot)
 	mutex_init(&iter->mutex);
 
 	/* Notify the tracer early; before we stop tracing. */
-	if (iter->trace && iter->trace->open)
+	if (iter->trace->open)
 		iter->trace->open(iter);
 
 	/* Annotate start of buffers if we had overruns */