Skip mounting /, just mark block device as ro if needed.

Change-Id: I7fbb636d296abc1caab6c7bf88017684c9df7759
diff --git a/fs_mgr/fs_mgr.c b/fs_mgr/fs_mgr.c
index f467f81..459daec 100644
--- a/fs_mgr/fs_mgr.c
+++ b/fs_mgr/fs_mgr.c
@@ -524,6 +524,14 @@
             continue;
         }
 
+        /* Skip mounting the root partition, as it will already have been mounted */
+        if (!strcmp(fstab->recs[i].mount_point, "/")) {
+            if ((fstab->recs[i].fs_mgr_flags & MS_RDONLY) != 0) {
+                fs_mgr_set_blk_ro(fstab->recs[i].blk_device);
+            }
+            continue;
+        }
+
         /* Translate LABEL= file system labels into block devices */
         if (!strcmp(fstab->recs[i].fs_type, "ext2") ||
             !strcmp(fstab->recs[i].fs_type, "ext3") ||