xfs: fix a couple error sequence jumps in xfs_mountfs()

xfs_mountfs() has a couple failure conditions that do not jump to the
correct labels. Specifically:

- xfs_initialize_perag_data() failure does not deallocate the log even
  though it occurs after log initialization
- xfs_mount_reset_sbqflags() failure returns the error directly rather
  than jump to the error sequence

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>