Bug#968300: doesn't build without real root

[Jakub Wilk]

>After some discussion on IRC it was found out that the CDPATH 
>environment variable was set which causes "cd debian/$pkg" to write the 
>directory name to stdout which was then picked up by "xargs rm".
>(Thanks to Jakub Wilk.)
>
>This could be worked around by always using "cd whatever >/dev/null",

Better work-around is using "cd ./whatever", so that CDPATH is not taken 
into account at all.

-- 
Jakub Wilk