pad: Remove unneeded 64bit upcast in debug trace

The hook->hook_id is a gulong for which there are no portability issues
when tracing in printf format with %lu. So use %lu and remove the upcast
to 64 bit. This makes the code more consistent with everything else
tracing that hook_id and other gulong id.
8 jobs for pad-cleanup in 13 minutes and 20 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Preparation
passed #90139
gst indent

00:00:14

passed #90138
manifest

00:00:35

 
  Build
passed #90140
build fedora x86_64

00:03:23

 
  Test
passed #90141
check fedora

00:03:18

 
  Full Builds
passed #90142
build android arm64 api28

00:03:47

passed #90144
build cerbero cross win32

00:05:44

passed #90145
build cerbero cross win64

00:05:52

passed #90143
build cerbero fedora x86_64

00:06:04