Check mkarchroot's return code

We weren't doing this before, and after build steps were
being run even if the build failed or if the user cancelled
the build

Signed-off-by: Aaron Griffin <aaronmgriffin@gmail.com>

makechrootpkg

@@ -218,8 +218,7 @@ EOF
 ) > "$uniondir/chrootbuild"
 chmod +x "$uniondir/chrootbuild"
 
-mkarchroot -r "/chrootbuild" "$uniondir"
-
+if mkarchroot -r "/chrootbuild" "$uniondir"; then
     source ${WORKDIR}/PKGBUILD
 
     if [ -n "$add_to_db" ]; then
@@ -238,6 +237,10 @@ if [ -z "$(mount | grep ${chrootdir}/union/srcdest)" ]; then
         echo "Moving downloaded source files to ${WORKDIR}"
         mv ${chrootdir}/union/srcdest/* ${WORKDIR}
     fi
+else
+    #just in case. We returned 1, make sure we fail
+    touch ${chrootdir}/rw/build/BUILD_FAILED
+fi
 
 if [ -e ${chrootdir}/rw/build/BUILD_FAILED ]; then
     echo "Build failed, check $chrootdir/rw/build"