kino/avi.cc: initialize variable

kino/avi.cc: initialize variable

Fixes Coverity CID 709439: Uninitialized scalar field (UNINIT_CTOR)
Non-static class member field "dvinfo.dwDVAAuxCtl1" is not initialized in this constructor nor in any functions that it calls.
Non-static class member field "dvinfo.dwDVAAuxCtl" is not initialized in this constructor nor in any functions that it calls.
Non-static class member field "dvinfo.dwDVAAuxSrc1" is not initialized in this constructor nor in any functions that it calls.
Non-static class member field "dvinfo.dwDVAAuxSrc" is not initialized in this constructor nor in any functions that it calls.
Non-static class member field "dvinfo.dwDVReserved" is not initialized in this constructor nor in any functions that it calls.
Non-static class member field "dvinfo.dwDVVAuxCtl" is not initialized in this constructor nor in any functions that it calls.
Non-static class member field "dvinfo.dwDVVAuxSrc" is not initialized in this constructor nor in any functions that it calls.