session: Migrate username mapping code into its own function
session: Migrate username mapping code into its own function

The perform_gssapi() function has gotten too long.

Reviewed-by: Peter <a316049dd34607c62d4611d63ab22a6454add223@redhat.com>

sgallagher/cockpit,petervo/cockpit,mareklibra/cockpit,cockpituous/cockpit,xhad/cockpit,garrett/cockpit,petervo/cockpit,martinpitt/cockpit,larskarlitski/cockpit,mareklibra/cockpit,xhad/cockpit,dperpeet/cockpit,moraleslazaro/cockpit,larsu/cockpit,larskarlitski/cockpit,sgallagher/cockpit,larskarlitski/cockpit,harishanand95/cockpit,stefwalter/cockpit,deryni/cockpit,sgallagher/cockpit,cockpituous/cockpit,cockpituous/cockpit,SotolitoLabs/cockpit,andreasn/cockpit,petervo/cockpit,cockpituous/cockpit,petervo/cockpit,dperpeet/cockpit,martinpitt/cockpit,stefwalter/cockpit,andreasn/cockpit,larsu/cockpit,xhad/cockpit,sgallagher/cockpit,xhad/cockpit,stefwalter/cockpit,SotolitoLabs/cockpit,cockpituous/cockpit,vanloswang/cockpit,sgallagher/cockpit,garrett/cockpit,andreasn/cockpit,xhad/cockpit,larskarlitski/cockpit,michalskrivanek/cockpit,larsu/cockpit,arilivigni/cockpit,vanloswang/cockpit,michalskrivanek/cockpit,deryni/cockpit,mareklibra/cockpit,martinpitt/cockpit,cockpit-project/cockpit,dperpeet/cockpit,vanloswang/cockpit,SotolitoLabs/cockpit,cockpit-project/cockpit,cockpit-project/cockpit,mvollmer/cockpit,andreasn/cockpit,arilivigni/cockpit,harishanand95/cockpit,larsu/cockpit,michalskrivanek/cockpit,mareklibra/cockpit,xhad/cockpit,dperpeet/cockpit,arilivigni/cockpit,Scribery/cockpit,stefwalter/cockpit,moraleslazaro/cockpit,petervo/cockpit,mvollmer/cockpit,larsu/cockpit,Scribery/cockpit,moraleslazaro/cockpit,harishanand95/cockpit,Scribery/cockpit,vanloswang/cockpit,xhad/cockpit,arilivigni/cockpit,michalskrivanek/cockpit,stefwalter/cockpit,arilivigni/cockpit,petervo/cockpit,moraleslazaro/cockpit,deryni/cockpit,arilivigni/cockpit,mareklibra/cockpit,harishanand95/cockpit,vanloswang/cockpit,vanloswang/cockpit,cockpit-project/cockpit,andreasn/cockpit,vanloswang/cockpit,sgallagher/cockpit,Scribery/cockpit,andreasn/cockpit,dperpeet/cockpit,garrett/cockpit,martinpitt/cockpit,moraleslazaro/cockpit,dperpeet/cockpit,michalskrivanek/cockpit,cockpituous/cockpit,mvollmer/cockpit,stefwalter/cockpit,deryni/cockpit,moraleslazaro/cockpit,harishanand95/cockpit,larskarlitski/cockpit,mvollmer/cockpit,moraleslazaro/cockpit,SotolitoLabs/cockpit,petervo/cockpit,michalskrivanek/cockpit,stefwalter/cockpit,garrett/cockpit,larskarlitski/cockpit,harishanand95/cockpit,sgallagher/cockpit,Scribery/cockpit,dperpeet/cockpit,mareklibra/cockpit,deryni/cockpit,deryni/cockpit,Scribery/cockpit,mvollmer/cockpit,michalskrivanek/cockpit,andreasn/cockpit,martinpitt/cockpit,harishanand95/cockpit,cockpit-project/cockpit,garrett/cockpit,larsu/cockpit,deryni/cockpit,SotolitoLabs/cockpit,SotolitoLabs/cockpit,arilivigni/cockpit,SotolitoLabs/cockpit,mareklibra/cockpit,Scribery/cockpit,larskarlitski/cockpit