Since we're adding checkpatch rules to enforce 4-line multiline comment
format, i.e. with lone /* and */, this script can be run on existing
code so that the comment style does not become inconsistent within a
file.
The alternative to awk-in-a-shell-script could be Perl, which also
supports -i directly, but a2p seems to have bitrotten and I didn't quite
feel like writing this twice...
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>