platform/x86: think-lmi: Fix memory leaks when parsing ThinkStation WMI strings

My previous commit introduced a memory leak where the item allocated
from tlmi_setting was not freed.
This commit also renames it to avoid confusion with the similarly name
variable in the same function.

Fixes: 8a02d70 ("platform/x86: think-lmi: Add possible_values for ThinkStation")
Reported-by: Mirsad Todorovac <mirsad.todorovac@alu.unizg.hr>
Link: https://lore.kernel.org/lkml/df26ff45-8933-f2b3-25f4-6ee51ccda7d8@gmx.de/T/
Signed-off-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Link: https://lore.kernel.org/r/20230403013120.2105-1-mpearson-lenovo@squebb.ca
Tested-by: Mario Limonciello <mario.limonciello@amd.com>
Tested-by: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

Author: mrhpearson

drivers/platform/x86/think-lmi.c

@@ -1459,10 +1459,10 @@ static int tlmi_analyze(void)
 			 * name string.
 			 * Try and pull that out if it's available.
 			 */
-			char *item, *optstart, *optend;
+			char *optitem, *optstart, *optend;
 
-			if (!tlmi_setting(setting->index, &item, LENOVO_BIOS_SETTING_GUID)) {
-				optstart = strstr(item, "[Optional:");
+			if (!tlmi_setting(setting->index, &optitem, LENOVO_BIOS_SETTING_GUID)) {
+				optstart = strstr(optitem, "[Optional:");
 				if (optstart) {
 					optstart += strlen("[Optional:");
 					optend = strstr(optstart, "]");
@@ -1471,6 +1471,7 @@ static int tlmi_analyze(void)
 							kstrndup(optstart, optend - optstart,
 									GFP_KERNEL);
 				}
+				kfree(optitem);
 			}
 		}
 		/*