oh-installfiles: In mkdir cmd, rm / and 1+ chars.

Previously, a pattern like `/usr/include/` in <binpkg>.pkg/files would cause
oh-installfiles to run `mkdir -p <binpkg>.data//usr/include` and install headers
in `<binpkg>.data/usr/include/include/`.

Before:

    $ pkg=foo
    $ file=/usr/include
    $ echo mkdir -p "${pkg}.data/${file%/*}"
    mkdir -p foo.data//usr
    $ file=/usr/include/
    $ echo mkdir -p "${pkg}.data/${file%/*}"
    mkdir -p foo.data//usr/include

After:

    $ pkg=foo
    $ file=/usr/include
    $ echo mkdir -p "${pkg}.data/${file%/?*}"
    mkdir -p foo.data//usr
    $ file=/usr/include/
    $ echo mkdir -p "${pkg}.data/${file%/?*}"
    mkdir -p foo.data//usr

0 files changed, 0 insertions, 0 deletions