package/matio: add upstream security fixes

Fix the following CVEs:
 - CVE-2019-17533: Mat_VarReadNextInfo4 in mat4.c in MATIO 1.5.17 omits
   a certain '\0' character, leading to a heap-based buffer over-read in
   strdup_vprintf when uninitialized memory is accessed.
 - CVE-2019-20017: A stack-based buffer over-read was discovered in
   Mat_VarReadNextInfo5 in mat5.c in matio 1.5.17.
 - CVE-2019-20018: A stack-based buffer over-read was discovered in
   ReadNextCell in mat5.c in matio 1.5.17.
 - CVE-2019-20020: A stack-based buffer over-read was discovered in
   ReadNextStructField in mat5.c in matio 1.5.17.
 - CVE-2019-20052: A memory leak was discovered in Mat_VarCalloc in
   mat.c in matio 1.5.17 because SafeMulDims does not consider the
   rank==0 case.

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>