Drop old BSC references in fd check configure option

Change-Id: I053c2bfe461aa82085e7dac1cdcc95dd77219949
diff --git a/src/select.c b/src/select.c
index 774056a..496beea 100644
--- a/src/select.c
+++ b/src/select.c
@@ -121,7 +121,7 @@
 	if (fd->fd > maxfd)
 		maxfd = fd->fd;
 
-#ifdef BSC_FD_CHECK
+#ifdef OSMO_FD_CHECK
 	if (osmo_fd_is_registered(fd)) {
 		fprintf(stderr, "Adding a osmo_fd that is already in the list.\n");
 		return 0;