Correct comment typos in a couple files

Correct typos in a couple files.  These were noticed while
researching code paths.  Comment changes only.  No code change.
afs/afs_stats.h has source file names updated on several lines.
Many source file name comments are wrong in this file.
I didn't attempt to correct them all, just the ones I bumped
into.  If I bump into others in the future I'll fix them then.
rx/rx_call.h has source of enumerated types corrected.

Change-Id: Ie78b7f20b5c9c2261ec8a73701e77bdfbabd8465
Reviewed-on: http://gerrit.openafs.org/11172
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Chas Williams - CONTRACTOR <chas@cmf.nrl.navy.mil>
Reviewed-by: Michael Meffie <mmeffie@sinenomine.net>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>