Propagate error code from rpmbuid

Fixes qubesos/qubes-issues#1099

build_template_rpm

@@ -1,6 +1,8 @@
 #!/bin/sh
 NAME=$1
 
+set -e
+
 if [ x$NAME = x ] ; then
 echo "usage $0 <template_name>"
 exit 1
@@ -15,6 +17,7 @@ if [ -d qubeized_images/$NAME/untrusted_appmenus ]; then
     for f in whitelisted-appmenus.list vm-whitelisted-appmenus.list netvm-whitelisted-appmenus.list; do
         grep '^[a-zA-Z0-9.()_-]\+.desktop$' $srcdir/$f > appmenus/$f
     done
+    trap "rm -rf appmenus-$$ appmenus" EXIT
 fi
 
 rpmbuild --target noarch \
@@ -23,7 +26,3 @@ rpmbuild --target noarch \
          --define "_topdir $PWD/rpmbuild" \
          --define "_tmppath $PWD/rpmbuild/tmp" \
          -bb templates.spec
-
-if [ -d appmenus-$$ ]; then
-    rm -rf appmenus-$$ appmenus
-fi