nfsd: nfs4callback encode_stateid helper function
nfsd: nfs4callback encode_stateid helper function

To be used also for the pnfs cb_layoutrecall callback

Signed-off-by: Benny Halevy <23c997c90eb8537635e9392d48e7af1bf1b2ca22@panasas.com>
[nfsd4: fix cb_recall encoding]
    "nfsd: nfs4callback encode_stateid helper function" forgot to reserve
    more space after return from the new helper.
Reported-by: Michael Groshans <f00e20fe91851ba3519fa2bbf6ec52a2efb070a3@citi.umich.edu>
Signed-off-by: Benny Halevy <23c997c90eb8537635e9392d48e7af1bf1b2ca22@panasas.com>
Signed-off-by: J. Bruce Fields <51738506c1b2ccb0761f23bdc612c93babf738ea@citi.umich.edu>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs