xfs: fix integer overflow in busy extent sort comparator

xfs: fix integer overflow in busy extent sort comparator

xfs_extent_busy_ag_cmp() subtracts two uint32_t values (group
numbers and block numbers) and returns the result as s32. When
the difference exceeds INT_MAX, the result overflows and the sort
order is corrupted.

Use cmp_int() instead, as was done in commit 362c49098086 ("xfs:
fix integer overflow in bmap intent sort comparator").

Fixes: 4a137e09151e ("xfs: keep a reference to the pag for busy extents")
Signed-off-by: Yuto Ohnuki <ytohnuki@amazon.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Carlos Maiolino <cem@kernel.org>