Pull nfsd fixes from Chuck Lever:

 - Fix an export leak

 - Fix a potential tracepoint crash

* tag 'nfsd-6.1-4' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux:
  nfsd: put the export reference in nfsd4_verify_deleg_dentry
  nfsd: fix use-after-free in nfsd_file_do_acquire tracepoint