sprintf_linter() fails on complex input

[MichaelChirico]

Found in r-devel:

https://github.com/r-devel/r-svn/blob/5da93fa94cd61d510acff8e8975e429a68c839d8/src/library/base/R/all.equal.R#L228-L229

lintr::lint("src/library/base/R/all.equal.R", lintr::sprintf_linter())
# Error: Linter 'sprintf_linter' failed in /usr/local/google/home/chiricom/svn/r-devel/src/library/base/R/all.equal.R: <text>:1:65: unexpected symbol
# 1: sprintf("Class definitions are not identical%s",if(isTRUE(ae))""elsepaste