platform/x86: thinkpad_acpi: Fix compiler warning about uninitialized err variable

err is always set because if we get here then dytc_profile_available
is always one of DYTC_FUNCMODE_MMC or DYTC_FUNCMODE_PSC, but the
compiler cannot now that, so initialize err to 0 to avoid a
compiler warning about err being uninitialized.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20220309170532.343384-1-hdegoede@redhat.com

drivers/platform/x86/thinkpad_acpi.c

@@ -10344,7 +10344,7 @@ static int dytc_profile_set(struct platform_profile_handler *pprof,
 static void dytc_profile_refresh(void)
 {
 	enum platform_profile_option profile;
-	int output, err;
+	int output, err = 0;
 	int perfmode;
 
 	mutex_lock(&dytc_mutex);