Fiemap has this rather convoluted logic to calculate the number of extents to
query. This introduces needless complexity with no real benefit. Remove
num_extents and instead hardcode the number of extents we query for in a single
go to 32. No functional changes
Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Eric Sandeen <sandeen@sandeen.net>