ia64: trivial spelling fixes

s/seralize/serialize/ .....three different places

Link: https://lkml.kernel.org/r/YFY+9uwvNLeb/3Ab@Gentoo


Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>