pprior code "converts" every icmp type - of which only 3 actually get changed (rest keep same value anyhow!). If also uses a SWITCH {} construct rather than lookup + foreach, which is longer and less efficient. (cherry picked from commit 0ce1667bc6fe80ef8e6b4d0d6d38d9859d5f4d94)
Simplify icmp conversion
pprior code "converts" every icmp type - of which only 3 actually get changed (rest keep same value anyhow!). If also uses a SWITCH {} construct rather than lookup + foreach, which is longer and less efficient.
(cherry picked from commit 0ce1667bc6fe80ef8e6b4d0d6d38d9859d5f4d94)