net: sched: pie: fix alignment in struct instances

Make the alignment in the initialization of the struct instances
consistent in the file.
Signed-off-by: NMohit P. Tahiliani <tahiliani@nitk.edu.in>
Signed-off-by: NLeslie Monis <lesliemonis@gmail.com>
Signed-off-by: NGautam Ramakrishnan <gautamramk@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>