orangefs: fix out-of-bounds fsid access

[ Upstream commit 53e4efa470d5fc6a96662d2d3322cfc925818517 ]

Arnd Bergmann sent a patch to fsdevel, he says:

"orangefs_statfs() copies two consecutive fields of the superblock into
the statfs structure, which triggers a warning from the string fortification
helpers"

Jan Kara suggested an alternate way to do the patch to make it more readable.

I ran both ideas through xfstests and both seem fine. This patch
is based on Jan Kara's suggestion.

Signed-off-by: Mike Marshall <hubcap@omnibond.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
(cherry picked from commit b90176a9553775e23966650e445b1866e62e4924)
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>