scsi: ibmvscsi: Make some functions static

Fix the following warning:

drivers/scsi/ibmvscsi/ibmvscsi.c:2387:12: warning: symbol
'ibmvscsi_module_init' was not declared. Should it be static?
drivers/scsi/ibmvscsi/ibmvscsi.c:2409:13: warning: symbol
'ibmvscsi_module_exit' was not declared. Should it be static?

Link: https://lore.kernel.org/r/20200520091036.247286-1-chentao107@huawei.com
Signed-off-by: Chen Tao <chentao107@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/ibmvscsi/ibmvscsi.c

@@ -2388,7 +2388,7 @@ static struct vio_driver ibmvscsi_driver = {
 static struct srp_function_template ibmvscsi_transport_functions = {
 };
 
-int __init ibmvscsi_module_init(void)
+static int __init ibmvscsi_module_init(void)
 {
 	int ret;
 
@@ -2410,7 +2410,7 @@ int __init ibmvscsi_module_init(void)
 	return ret;
 }
 
-void __exit ibmvscsi_module_exit(void)
+static void __exit ibmvscsi_module_exit(void)
 {
 	vio_unregister_driver(&ibmvscsi_driver);
 	srp_release_transport(ibmvscsi_transport_template);