uuid: fix incorrect uuid_equal conversion in test_uuid_test

Fixes: df33767d ("uuid: hoist helpers uuid_equal() and uuid_copy() from xfs")
Reported-by: kernel test robot <xiaolong.ye@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

uuid: hoist helpers uuid_equal() and uuid_copy() from xfs

These helper are used to compare and copy two uuid_t type objects.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
[hch: also provide the respective guid_ versions]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

uuid: rename uuid types

Our "little endian" UUID really is a Wintel GUID, so rename it and its
helpers such (guid_t). The big endian UUID is the only true one, so
give it the name uuid_t. The uuid_le and uuid_be names are retained for
now, but will hopefully go away soon. The exception to that are the _cmp
helpers that will be replaced by better primitives ASAP and thus don't
get the new names.

Also the _to_bin helpers are named to match the better named uuid_parse
routine in userspace.

Also remove the existing typedef in XFS that's now been superceeded by
the generic type name.

Signed-off-by: Christoph Hellwig <hch@lst.de>
[andy: also update the UUID_LE/UUID_BE macros including fallout]
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Signed-off-by: Christoph Hellwig <hch@lst.de>

lib/uuid: add a test module

It appears that somehow I missed a test of the latest UUID rework which
landed in the kernel. Present a small test module to avoid such cases
in the future.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>