Actually wait on the provided fd in __read

Change-Id: Iad7f6e8529741c4ff8851c4db44e8141403d3810

linenoise.c

diff --git a/linenoise.c b/linenoise.c
index 503355b..6d37b72 100644
--- a/linenoise.c
+++ b/linenoise.c
@@ -145,8 +145,8 @@
     if (len == 0) return 0;
 
     for (;;) {
-      mxio_wait_fd(0, MXIO_EVT_READABLE, NULL, MX_TIME_INFINITE);
-      if ((nread = read(0, buf, len)))
+      mxio_wait_fd(fd, MXIO_EVT_READABLE, NULL, MX_TIME_INFINITE);
+      if ((nread = read(fd, buf, len)))
           return nread;
     }