Merge branch 'rj/xdiff-prepare-plug-leak-on-error-codepath' into maint

A small memory leak in an error codepath has been plugged in xdiff
code.

* rj/xdiff-prepare-plug-leak-on-error-codepath:
  xdiff/xprepare: fix a memory leak
  xdiff/xprepare: use the XDF_DIFF_ALG() macro to access flag bits
