Add "none" to list of skipped filesystems in automatic drive detection

[Ben Klein]

In programs/winecfg/drivedetect.c, there is a list of skipped filesystem types:
static const char * const ignored_fstypes[]

I propose that "none" be added to this list. The "none" type is used
in fstab in combination with options such as "bind" and "rbind". I
have such entries in my fstab for my various chroots that I use to
build packages of Wine.