In 676595f9

 (Prefix package functions with pkg_/pkgbase_, 2014-04-05),
votes_for_pkgname() was renamed to pkgbase_votes_from_name() without
changing the semantics. Slightly adapt the implementation and interpret
the argument as a package base name instead of a package name. Also fix
the call site.

Reported-by: Felix Yan <felixonmars@gmail.com>
Signed-off-by: Lukas Fleischer <archlinux@cryptocrack.de>