possible double-free in comps_doc.c if xmlTextWriter functions fail

[ret2libc]

In function comps_doc_xml() in comps_doc.c, the dict object is destroyed at

libcomps/libcomps/src/comps_doc.c

Line 731 in 2ed0fe5

COMPS_OBJECT_DESTROY(dict);

, however there are many other error paths where the object is destroyed again, possibly causing double-free (e.g.

libcomps/libcomps/src/comps_doc.c

Line 737 in 2ed0fe5

COMPS_OBJECT_DESTROY(dict);

).

This was probably the result of a wrong copy-paste, where dict should have been replaced with mdict but it wasn't.