abuild: fix cross compilation undeps()

"apk del" now returns error if the package name does not exist.
Thus when cross compiling, always install the virtual
.makedepends-$pkgname name for chroot also since undeps() will
try to uninstall it always.

abuild.in

@@ -1812,7 +1812,7 @@ builddeps() {
 			--simulate --quiet $builddeps || return 1
 		$SUDO_APK add --repository "$abuildrepo" $apk_opt_wait \
 			--virtual .makedepends-$pkgname $builddeps || return 1
-		if [ -n "$hostdeps" ]; then
+		if cross_compiling; then
 			$SUDO_APK add --root "$CBUILDROOT" --repository "$abuildrepo" $apk_opt_wait \
 				--simulate --quiet $hostdeps || return 1
 			$SUDO_APK add --root "$CBUILDROOT" --repository "$abuildrepo" $apk_opt_wait \