platform/x86: thinkpad_acpi: Fix old style declaration GCC warning

Fix an [-Wold-style-declaration] GCC warning by moving the inline
keyword before the return type.
Signed-off-by: NTobias Klauser <tklauser@distanz.ch>
Acked-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NDarren Hart <dvhart@linux.intel.com>

drivers/platform/x86/thinkpad_acpi.c

@@ -7771,7 +7771,7 @@ static struct ibm_struct volume_driver_data = {
 
 #define alsa_card NULL
 
-static void inline volume_alsa_notify_change(void)
+static inline void volume_alsa_notify_change(void)
 {
 }