printers: Use self variable to match coding style

11 jobs for printers-g-declare-type in 3 minutes and 48 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Build
passed #199928
build

00:02:25

 
  Test
passed #199930
asan

00:01:22

passed #199929
test

00:01:01

 
  Manual
manual #199935
allowed to fail manual
armv8
manual #199931
allowed to fail manual
flatpak
manual #199934
allowed to fail manual
msan
manual #199936
allowed to fail manual
ppc64le
manual #199932
allowed to fail manual
tsan
manual #199933
allowed to fail manual
ubsan
 
  Review
manual #199937
allowed to fail manual
review
manual #199938
allowed to fail manual
stop_review