platform/x86: think-lmi: Fix memory leak when showing current settings

When retriving a item string with tlmi_setting(), the result has to be
freed using kfree(). In current_value_show() however, malformed
item strings are not freed, causing a memory leak.
Fix this by eliminating the early return responsible for this.

Reported-by: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
Link: https://lore.kernel.org/platform-driver-x86/01e920bc-5882-ba0c-dd15-868bf0eca0b8@alu.unizg.hr/T/#t
Tested-by: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
Fixes: 0fdf10e5

 ("platform/x86: think-lmi: Split current_value to reflect only the value")
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20230331213319.41040-1-W_Armin@gmx.de
Tested-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>