r222389 introduced a case where the NFSv4 client could loop in nfscl_getcl() when a forced dismount is in progress, because nfsv4_lock() will return 0 without sleeping when MNTK_UNMOUNTF is set. This patch fixes it so it won't loop calling nfsv4_lock() for this case.
r222389 introduced a case where the NFSv4 client could
loop in nfscl_getcl() when a forced dismount is in progress,
because nfsv4_lock() will return 0 without sleeping when
MNTK_UNMOUNTF is set.
This patch fixes it so it won't loop calling nfsv4_lock()
for this case.

MFC after:	2 weeks

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase