fs_mgr: support a unified fstab format.

Update fs_mgr to support more flags needed to unify the 3
fstabs currently in android into one.

Change-Id: Ie46cea61a5b19882c55098bdd70f39e78fb603be
diff --git a/init/builtins.c b/init/builtins.c
index dc7900e..0f9f131 100644
--- a/init/builtins.c
+++ b/init/builtins.c
@@ -464,6 +464,7 @@
     int child_ret = -1;
     int status;
     const char *prop;
+    struct fstab *fstab;
 
     if (nargs != 2) {
         return -1;
@@ -487,7 +488,9 @@
     } else if (pid == 0) {
         /* child, call fs_mgr_mount_all() */
         klog_set_level(6);  /* So we can see what fs_mgr_mount_all() does */
-        child_ret = fs_mgr_mount_all(args[1]);
+        fstab = fs_mgr_read_fstab(args[1]);
+        child_ret = fs_mgr_mount_all(fstab);
+        fs_mgr_free_fstab(fstab);
         if (child_ret == -1) {
             ERROR("fs_mgr_mount_all returned an error\n");
         }