Added missing ; in dep_target

The missing ; makes the DEPPKG= line run together with the VS= line which makes it similar to this

FreeBSD 8.2 /bin/sh results:

$  A=x B=$A;
$  echo $A
x
$  echo $B

$

The same with bash:

$ A=x B=$A;
$ echo $A
x
$ echo $B
x
Merge branch 'master' of git://github.com/peerst/erlang.mk