ftrace: Remove redundant initialization of variable ret

The variable ret is being initialized with a value that is never
read, it is being updated later on. The assignment is redundant and
can be removed.

Link: https://lkml.kernel.org/r/20210721120915.122278-1-colin.king@canonical.com

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

kernel/trace/ftrace.c

@@ -7545,7 +7545,7 @@ int ftrace_is_dead(void)
  */
 int register_ftrace_function(struct ftrace_ops *ops)
 {
-	int ret = -1;
+	int ret;
 
 	ftrace_ops_init(ops);