ibuffer-mark-by-content-regexp: don't depend on `cl-some'

* lisp/ibuf-ext.el (ibuffer-mark-by-content-regexp): Use `cl-dolist'
instead of `cl-some' to avoid a run-time dependency on cl-lib that
triggers an unreported bug similar to bug#38430.
1 job for master in 56 minutes and 25 seconds (queued for 2 seconds)
Status Job ID Name Coverage
failed #4401


Name Stage Failure
test-all Test
Makefile:319: recipe for target 'check-doit' failed
make[2]: *** [check-doit] Error 1
make[2]: Leaving directory '/builds/emacs/emacs/test'
Makefile:294: recipe for target 'check-expensive' failed
make[1]: *** [check-expensive] Error 2
make[1]: Leaving directory '/builds/emacs/emacs/test'
Makefile:959: recipe for target 'check-expensive' failed
make: *** [check-expensive] Error 2
ERROR: Job failed: exit code 1