[media] fix up oiio/null implementations

src/media/none.c

@@ -79,7 +79,7 @@ void none_printbanner(const notcurses* nc){
   fprintf(stderr, "\n Warning! Notcurses was built without multimedia support.\n");
 }
 
-const static ncvisual_implementation none_impl = {
+static const ncvisual_implementation none_impl = {
   .visual_init = none_init,
   .visual_printbanner = none_printbanner,
   .visual_blit = none_blit,

src/media/oiio.cpp

@@ -18,7 +18,10 @@ typedef struct ncvisual_details {
 auto oiio_details_init(void) -> ncvisual_details* {
   auto deets = static_cast<ncvisual_details*>(malloc(sizeof(ncvisual_details)));
   if(deets){
-    memset(deets, 0, sizeof(*deets));
+    deets->image = nullptr;
+    deets->frame = nullptr;
+    deets->ibuf = nullptr;
+    deets->framenum = 0;
   }
   return deets;
 }
@@ -31,7 +34,7 @@ auto oiio_details_destroy(ncvisual_details* deets) -> void {
 }
 
 auto oiio_create() -> ncvisual* {
-  auto nc = static_cast<ncvisual*>(malloc(sizeof(*nc)));
+  auto nc = static_cast<ncvisual*>(malloc(sizeof(ncvisual)));
   if(nc){
     memset(nc, 0, sizeof(*nc));
     if((nc->details = oiio_details_init()) == nullptr){