gprs_ns2_fr.c: Skip extraneous FIONBIO

The socket is marked non-blocking inside osmo_fd_register(), there
is no need to do it twice.

Change-Id: I2068ce8280357b14970d01e5c86de5c59c933650
diff --git a/src/gb/gprs_ns2_fr.c b/src/gb/gprs_ns2_fr.c
index 8befe1c..c774e11 100644
--- a/src/gb/gprs_ns2_fr.c
+++ b/src/gb/gprs_ns2_fr.c
@@ -303,7 +303,7 @@
 {
 	struct sockaddr_ll addr;
 	int ifindex;
-	int fd, rc, on = 1;
+	int fd, rc;
 
 	ifindex = devname2ifindex(ifname);
 	if (ifindex < 0) {
@@ -322,14 +322,6 @@
 		return fd;
 	}
 
-	if (ioctl(fd, FIONBIO, (unsigned char *)&on) < 0) {
-		LOGP(DLGLOBAL, LOGL_ERROR,
-			"cannot set this socket unblocking: %s\n",
-			strerror(errno));
-		close(fd);
-		return -EINVAL;
-	}
-
 	rc = bind(fd, (struct sockaddr *)&addr, sizeof(addr));
 	if (rc < 0) {
 		LOGP(DLNS, LOGL_ERROR, "Can not bind for interface %s\n", ifname);