A packet is tunnelled if the tunnel type is identified or if it has
an inner part.
Fix also some typos in RTE_PTYPE_INNER_L3_MASK and IP comments.
Fixes: f295a00a2b44 ("mbuf: add definitions of unified packet types")
Signed-off-by: Thomas Monjalon <thomas.monjalon@6wind.com>
Acked-by: Adrien Mazarguil <adrien.mazarguil@6wind.com>