hwmon: (amd_energy) fix allocation of hwmon_channel_info config

hwmon, specifically hwmon_num_channel_attrs, expects the config
array in the hwmon_channel_info structure to be terminated by
a zero entry.  amd_energy does not honor this convention.  As
result, a KASAN warning is possible.  Fix this by adding an
additional entry and setting it to zero.

Fixes: 8abee95 ("hwmon: Add amd_energy driver to report energy counters")

Signed-off-by: David Arcari <darcari@redhat.com>
Cc: Naveen Krishna Chatradhi <nchatrad@amd.com>
Cc: Jean Delvare <jdelvare@suse.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: David Arcari <darcari@redhat.com>
Acked-by: Naveen Krishna Chatradhi <nchatrad@amd.com>
Link: https://lore.kernel.org/r/20210107144707.6927-1-darcari@redhat.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

drivers/hwmon/amd_energy.c

@@ -222,7 +222,7 @@ static int amd_create_sensor(struct device *dev,
 	 */
 	cpus = num_present_cpus() / num_siblings;
 
-	s_config = devm_kcalloc(dev, cpus + sockets,
+	s_config = devm_kcalloc(dev, cpus + sockets + 1,
 				sizeof(u32), GFP_KERNEL);
 	if (!s_config)
 		return -ENOMEM;
@@ -254,6 +254,7 @@ static int amd_create_sensor(struct device *dev,
 			scnprintf(label_l[i], 10, "Esocket%u", (i - cpus));
 	}
 
+	s_config[i] = 0;
 	return 0;
 }