xfs: inobt can use perags in many more places than it does

xfs: inobt can use perags in many more places than it does

Source kernel commit: bab8b795185bf37801a4f7ee5c321eee288c2f10

Lots of code in the inobt infrastructure is passed both xfs_mount
and perags. We only need perags for the per-ag inode allocation
code, so reduce the duplication by passing only the perags as the
primary object.

This ends up reducing the code size by a bit:

text    data     bss     dec     hex filename
orig    1138878  323979     548 1463405  16546d (TOTALS)
patched 1138709  323979     548 1463236  1653c4 (TOTALS)

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>