doc: Fix regressions that made building guide too noisy
doc: Fix regressions that made building guide too noisy

The Makefile for building the guide respected the V=1 and automake
silent rules. Fix the regression introduced in #5834

Reviewed-by: Dominik Perpeet <f7830b2723a5db4fc185058b06cfab4b89a38da9@redhat.com>

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