nfsd4: fail when delegreturn gets a non-delegation stateid
nfsd4: fail when delegreturn gets a non-delegation stateid

Previous cleanup reveals an obvious (though harmless) bug: when
delegreturn gets a stateid that isn't for a delegation, it should return
an error rather than doing nothing.

Signed-off-by: J. Bruce Fields <51738506c1b2ccb0761f23bdc612c93babf738ea@citi.umich.edu>

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