xfs: rename the old_crc variable in xlog_recover_process

[ Upstream commit 0b737f4a ]

old_crc is a very misleading name.  Rename it to expected_crc as that
described the usage much better.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
Stable-dep-of: e747883c ("xfs: fix log CRC mismatches between i386 and other architectures")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>