misc/mke2fs.c: suppress 'Creating regular file' message with -q

[josch]

To check if the installed version of mke2fs is able to accept tarballs, I'm piping 10240 null-bytes (an empty tarball) into mke2fs. Unfortunately, mke2fs prints this on stdout:

Creating regular file [...]

and the -q flag has no effect. An easy workaround is to touch the file before running mke2fs but it would be nice if that were not necessary.