net: ppp: Mundane typo fixes in the file pppoe.c

s/procesing/processing/
s/comparations/comparisons/

Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>