Do not hide the return code of context2csv.

The wrapper script for the `context2csv` command should return the same
error code as the command itself.

We can't do that by using `set -e`, because then any error in
`context2csv` would cause the wrapper to immediately exit without
removing the temporary file. And using `trap` to make sure the file is
always removed regardless of how the script terminates could make the
script less portable (I don't remember how well `trap` is supported in
the various shells out there, and I can't be bothered to check right
now). So we simply capture the return code of `context2csv`, remove the
intermediate file, and explicitly exits the wrapper with the captured
return code.

Author: gouttegd

scripts/compat-context2csv.sh

@@ -1,4 +1,6 @@
 #!/bin/sh
 cat > $$.tmp
 odk-helper context2csv $$.tmp
+rc=$?
 rm $$.tmp
+exit $rc