pyang 2.6.0 tree format issue

[szabolcsszekely]

Hi,

With pyang 2.6.0, if you generate a yang tree from multiple independent yang modules, the module names after the first one are missing from the yang tree output. There are also multiple empty lines added between the different module contents (you can see this if you create a yang tree output from all the yang files from the standard RFC yang directory). pyang 2.5.0:

$ pyang -f tree params-1.yang params-2.yang
module: params-1
  +--rw main
     +--rw one?   string

module: params-2
  +--rw main
     +--rw two?   string

pyang 2.6.0:

$ pyang -f tree params-1.yang params-2.yang
module: params-1
  +--rw main
     +--rw one?   string

  +--rw main
     +--rw two?   string