percpu: use DEFINE_PER_CPU_SHARED_ALIGNED()

There are a few places where ___cacheline_aligned* is used with
DEFINE_PER_CPU().  Use DEFINE_PER_CPU_SHARED_ALIGNED() instead.

DEFINE_PER_CPU_SHARED_ALIGNED() applies alignment only on SMPs.  While
all other converted places used _in_smp variant or only get compiled
for SMP, net/rds used unconditional ____cacheline_aligned.  I don't
see any reason these data structures should be aligned on UP and thus
converted together.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Andy Grover <andy.grover@oracle.com>