Respect paths with spaces on --install

makepkg --install doesn't quote the absolute path, so if the path contains
spaces pacman -U fails.

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

scripts/makepkg.sh.in

@@ -2089,7 +2089,7 @@ install_package() {
 		fi
 	done
 
-	if ! run_pacman -U ${pkglist[@]}; then
+	if ! run_pacman -U "${pkglist[@]}"; then
 		warning "$(gettext "Failed to install built package(s).")"
 		return 0
 	fi