ia64: mca: drop redundant spinlock initialization

mlogbuf_rlock has declared and initialized by DEFINE_SPINLOCK,
so we don't need to spin_lock_init again, drop it.

Link: https://lkml.kernel.org/r/1652176897-4754-1-git-send-email-baihaowen@meizu.com


Signed-off-by: Haowen Bai <baihaowen@meizu.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>