Bug#5210: dpkg-source complains on substitution variables

[Mr Stuart Lamble <lamble@aurora.cc.monash.edu.au>]

Package: dpkg
Version: 1.4.0.2

When I was building up libelf0, I tried using  in debian/control:

Package: libelf
...
Package: libelf-dev

in an attempt to not have to edit the control file when libelf 1.0.0 comes
out. (yeah, I'm lazy. :) dpkg-source barfs on this, despite having setup
substvars properly, claiming that the package has two conflicting names,
libelf0 and libelf.

I worked around it by changing the s to 0, but as I read the manual,
it should know how to use substvars to do the required job. 'Course, I could
be showing off my ignorance here. :)