cleanup pbchk lints uncovered by #15483
#15483 touches a lot of files, which stirs up a lot of
git pbchk dust bunnies that rightfully ought to be addressed. These are almost all whitespaces changes, and mostly mechanical, but they are voluminous: my concern is that addressing them in #15483 will obscure an already large change (though this may be ameliorated by disabling whitespace diff in Gerrit).
After consulting with Robert, Andy, and Josh, I'm going to just do in a follow-up change. This should be wsdiff clean with respect to the prior change.