tracing/trivial: Remove cast from void*

Unnecessary cast from void* in assignment.

Signed-off-by: matt mooney <mfm@muteddisk.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 65fb077..ebd80d5 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1638,8 +1638,8 @@
 
 	ret = ftrace_avail_open(inode, file);
 	if (!ret) {
-		m = (struct seq_file *)file->private_data;
-		iter = (struct ftrace_iterator *)m->private;
+		m = file->private_data;
+		iter = m->private;
 		iter->flags = FTRACE_ITER_FAILURES;
 	}