Fix uninitialized variable reported by cppcheck
Fix uninitialized variable reported by cppcheck

tbeu/matio,MaartenBent/matio,tbeu/matio,tbeu/matio,NJannasch/matio,NJannasch/matio,martinichka/matio-coder,CBL-ORION/matio,tbeu/matio,CBL-ORION/matio-sf-mirror,telehan/libmatio,MaartenBent/matio,martinichka/matio-coder,MaartenBent/matio,MaartenBent/matio,CBL-ORION/matio,telehan/libmatio,martinichka/matio-coder,CBL-ORION/matio-sf-mirror