NFSv42: Don't fail clone() unless the OP_CLONE operation failed

NFSv42: Don't fail clone() unless the OP_CLONE operation failed

[ Upstream commit 56a23e3a021f6352c997826e57f47403a87a989b ]

The failure to retrieve post-op attributes has no bearing on whether or
not the clone operation itself was successful. We must therefore ignore
the return value of decode_getfattr() when looking at the success or
failure of nfs4_xdr_dec_clone().

Fixes: d0b29ec5fb41 ("nfs42: add CLONE xdr functions")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>