sgsn: Check the return value of osmo_fd_register
We can't do much in case the fd is failing to be registered.
There should be a timeout that is catching this and it might
be able to repair it self.
Fixes: Coverity CID#1302854
diff --git a/openbsc/src/gprs/sgsn_ares.c b/openbsc/src/gprs/sgsn_ares.c
index eabf940..dd1bdb5 100644
--- a/openbsc/src/gprs/sgsn_ares.c
+++ b/openbsc/src/gprs/sgsn_ares.c
@@ -114,7 +114,8 @@
ufd->fd.fd = fd;
ufd->fd.cb = ares_osmo_fd_cb;
ufd->fd.data = data;
- osmo_fd_register(&ufd->fd);
+ if (osmo_fd_register(&ufd->fd) != 0)
+ LOGP(DGPRS, LOGL_ERROR, "Failed to register C-ares fd (%d)\n", fd);
llist_add(&ufd->head, &sgsn->ares_fds);
update_fd: