pyang_plugins: Replace map() with list comprehension
pyang_plugins: Replace map() with list comprehension

Mostly, using the list comprehension is more efficiently than map() with
"lambda".
This patch replaces map() + "lambda" by the list comprehension.

Signed-off-by: IWASE Yusuke <bb80e84cc9f5a8f01385872ee89032beb5d4eba7@gmail.com>

j-kato/gobgp,a16/gobgp,Dipsingh/gobgp,tamihiro/gobgp,a16/gobgp,osrg/gobgp,fujita/gobgp,a16/gobgp,fujita/gobgp,Dipsingh/gobgp,j-kato/gobgp,a16/gobgp,j-kato/gobgp,fujita/gobgp,Dipsingh/gobgp,a16/gobgp,a16/gobgp,a16/gobgp,osrg/gobgp,tamihiro/gobgp,osrg/gobgp,osrg/gobgp,fujita/gobgp,tamihiro/gobgp,tamihiro/gobgp