hwmon: (dell-smm) Fix warning on /proc/i8k creation error

commit dbd3e6e upstream.

The removal function is called regardless of whether
/proc/i8k was created successfully or not, the later
causing a WARN() on module removal.
Fix that by only registering the removal function
if /proc/i8k was created successfully.

Tested on a Inspiron 3505.

Fixes: 039ae58 ("hwmon: Allow to compile dell-smm-hwmon driver without /proc/i8k")
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Acked-by: Pali Rohár <pali@kernel.org>
Link: https://lore.kernel.org/r/20211112171440.59006-1-W_Armin@gmx.de
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/hwmon/dell-smm-hwmon.c

@@ -603,15 +603,18 @@ static const struct proc_ops i8k_proc_ops = {
 	.proc_ioctl	= i8k_ioctl,
 };
 
+static struct proc_dir_entry *entry;
+
 static void __init i8k_init_procfs(void)
 {
 	/* Register the proc entry */
-	proc_create("i8k", 0, NULL, &i8k_proc_ops);
+	entry = proc_create("i8k", 0, NULL, &i8k_proc_ops);
 }
 
 static void __exit i8k_exit_procfs(void)
 {
-	remove_proc_entry("i8k", NULL);
+	if (entry)
+		remove_proc_entry("i8k", NULL);
 }
 
 #else