package/exfatprogs: fix compile failure node may be used uninitialized

Fixes:

  - http://autobuild.buildroot.net/results/5c5/5c5d71fde80a4f2f027085bdb0fae9fb76ab9d32



  fsck.c:1062:18: error: 'node' may be used uninitialized in this function [-Werror=maybe-uninitialized]
       node->parent = dir;
                    ^
  fsck.c:870:22: note: 'node' was declared here
    struct exfat_inode *node;
                        ^

Signed-off-by: Peter Seiderer <ps.report@gmx.net>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>