kprobes: Remove unneeded warnings from __arm_kprobe_ftrace()

Remove unneeded warnings for handled errors from __arm_kprobe_ftrace()
because all caller handled the error correctly.

Link: https://lore.kernel.org/all/177261531182.1312989.8737778408503961141.stgit@mhiramat.tok.corp.google.com/

Reported-by: Zw Tang <shicenci@gmail.com>
Closes: https://lore.kernel.org/all/CAPHJ_V+J6YDb_wX2nhXU6kh466Dt_nyDSas-1i_Y8s7tqY-Mzw@mail.gmail.com/
Fixes: 9c89bb8 ("kprobes: treewide: Cleanup the error messages for kprobes")
Cc: stable@vger.kernel.org
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>

Author: mhiramat

kernel/kprobes.c

@@ -1144,12 +1144,12 @@ static int __arm_kprobe_ftrace(struct kprobe *p, struct ftrace_ops *ops,
 	lockdep_assert_held(&kprobe_mutex);
 
 	ret = ftrace_set_filter_ip(ops, (unsigned long)p->addr, 0, 0);
-	if (WARN_ONCE(ret < 0, "Failed to arm kprobe-ftrace at %pS (error %d)\n", p->addr, ret))
+	if (ret < 0)
 		return ret;
 
 	if (*cnt == 0) {
 		ret = register_ftrace_function(ops);
-		if (WARN(ret < 0, "Failed to register kprobe-ftrace (error %d)\n", ret)) {
+		if (ret < 0) {
 			/*
 			 * At this point, sinec ops is not registered, we should be sefe from
 			 * registering empty filter.