xfs: remove rt-wrappers from xfs_format.h

xfs: remove rt-wrappers from xfs_format.h

Source kernel commit: 3abfe6c2759e2e3000b13f8ce8a1a325e80987a1

xfs_format.h has a bunch odd wrappers for helper functions and mount
structure access using RT* prefixes.  Replace them with their open coded
versions (for those that weren't entirely unused) and remove the wrappers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
Reviewed-by: Bill O'Donnell <bodonnel@redhat.com>