Minor change to match naming convention in other collectors.
Initialize the proc or sys FS instance once while initializing
each collector instead of re-creating for each metric update.
Signed-off-by: Paul Gier <pgier@redhat.com>
PIDs can vanish (exit) from /proc/ between gathering the list of PIDs
and getting all of their stats.
* Ignore file not found errors.
* Explicitly count the PIDs we find.
* Cleanup some error style issues.
Signed-off-by: Ben Kochie <superq@gmail.com>