timekeeping/debug: No need to check return value of debugfs_create functions

When calling debugfs functions, there is no need to ever check the return
value.  The function can work or not, but the code logic should never do
something different based on this.
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Stephen Boyd <sboyd@kernel.org>
Link: https://lkml.kernel.org/r/20190122152151.16139-43-gregkh@linuxfoundation.org

kernel/time/timekeeping_debug.c

@@ -37,15 +37,8 @@ DEFINE_SHOW_ATTRIBUTE(tk_debug_sleep_time);
 
 static int __init tk_debug_sleep_time_init(void)
 {
-	struct dentry *d;
-
-	d = debugfs_create_file("sleep_time", 0444, NULL, NULL,
-		&tk_debug_sleep_time_fops);
-	if (!d) {
-		pr_err("Failed to create sleep_time debug file\n");
-		return -ENOMEM;
-	}
-
+	debugfs_create_file("sleep_time", 0444, NULL, NULL,
+			    &tk_debug_sleep_time_fops);
 	return 0;
 }
 late_initcall(tk_debug_sleep_time_init);