soc: qcom: apr: make remove callback of apr driver void returned

Since commit fc7a6209d5 ("bus: Make remove callback return void")
forces bus_type::remove be void-returned, it doesn't make much sense
for any bus based driver implementing remove callbalk to return
non-void to its caller.

As such, change the remove function for apr bus based drivers to
return void.

Signed-off-by: Dawei Li <set_pte_at@outlook.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/TYCP286MB23232B7968D34DB8323B0F16CAFB9@TYCP286MB2323.JPNP286.PROD.OUTLOOK.COM

include/linux/soc/qcom/apr.h

@@ -153,7 +153,7 @@ typedef struct apr_device gpr_device_t;
 
 struct apr_driver {
 	int	(*probe)(struct apr_device *sl);
-	int	(*remove)(struct apr_device *sl);
+	void	(*remove)(struct apr_device *sl);
 	int	(*callback)(struct apr_device *a,
 			    struct apr_resp_pkt *d);
 	int	(*gpr_callback)(struct gpr_resp_pkt *d, void *data, int op);

sound/soc/qcom/qdsp6/q6core.c

@@ -339,7 +339,7 @@ static int q6core_probe(struct apr_device *adev)
 	return 0;
 }
 
-static int q6core_exit(struct apr_device *adev)
+static void q6core_exit(struct apr_device *adev)
 {
 	struct q6core *core = dev_get_drvdata(&adev->dev);
 
@@ -350,8 +350,6 @@ static int q6core_exit(struct apr_device *adev)
 
 	g_core = NULL;
 	kfree(core);
-
-	return 0;
 }
 
 #ifdef CONFIG_OF