makepkg: abort on missing download agent

makepkg would not abort on a missing download agent due to the
output variable being declared local on the same line as the
function call in the assignment. That would result in strange output
such as:

==> Retrieving Sources...
==> ERROR: There is no agent set up to handle foo URLs. Check /etc/makepkg.conf.
    Aborting...
  -> Downloading foobaz...
/home/arch/code/pacman/scripts/makepkg: line 401: foo://foobaz: No such file or directory
==> ERROR: Failure while downloading foobaz
    Aborting...

Signed-off-by: Allan McRae <allan@archlinux.org>
Signed-off-by: Dan McGee <dan@archlinux.org>

0 files changed, 0 insertions, 0 deletions