s390/sclp: avoid compile warning in sclp_pci_report

Fix the initialization of a local variable to remove this warning:

All warnings (new ones prefixed by >>):

   drivers/s390/char/sclp_pci.c: In function 'sclp_pci_report':
>> drivers/s390/char/sclp_pci.c:127:9: warning: missing braces around initializer [-Wmissing-braces]
     struct sclp_req req = {0};
            ^
   drivers/s390/char/sclp_pci.c:127:9: warning: (near initialization for 'req.list') [-Wmissing-braces]

Fixes: 12283a40 "s390/sclp: add error notification command"
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

drivers/s390/char/sclp_pci.c

@@ -124,7 +124,7 @@ int sclp_pci_report(struct zpci_report_error_header *report, u32 fh, u32 fid)
 {
 	DECLARE_COMPLETION_ONSTACK(completion);
 	struct err_notify_sccb *sccb;
-	struct sclp_req req = {0};
+	struct sclp_req req;
 	int ret;
 
 	ret = sclp_pci_check_report(report);
@@ -147,6 +147,7 @@ int sclp_pci_report(struct zpci_report_error_header *report, u32 fh, u32 fid)
 		goto out_unregister;
 	}
 
+	memset(&req, 0, sizeof(req));
 	req.callback_data = &completion;
 	req.callback = sclp_pci_callback;
 	req.command = SCLP_CMDW_WRITE_EVENT_DATA;