nbd/client: fix nbd_send_request to return int

Fix nbd_send_request to return int, as it returns a return value
of nbd_write (which is int), and the only user of nbd_send_request's
return value (nbd_co_send_request) consider it as int too.
Signed-off-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20170804151440.320927-5-vsementsov@virtuozzo.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

include/block/nbd.h

@@ -163,7 +163,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name,
                           Error **errp);
 int nbd_init(int fd, QIOChannelSocket *sioc, NBDExportInfo *info,
              Error **errp);
-ssize_t nbd_send_request(QIOChannel *ioc, NBDRequest *request);
+int nbd_send_request(QIOChannel *ioc, NBDRequest *request);
 int nbd_receive_reply(QIOChannel *ioc, NBDReply *reply, Error **errp);
 int nbd_client(int fd);
 int nbd_disconnect(int fd);

nbd/client.c

@@ -896,7 +896,7 @@ int nbd_disconnect(int fd)
 }
 #endif
 
-ssize_t nbd_send_request(QIOChannel *ioc, NBDRequest *request)
+int nbd_send_request(QIOChannel *ioc, NBDRequest *request)
 {
     uint8_t buf[NBD_REQUEST_SIZE];