USD: Release ImBuf objects during export

ImBuf objects need to be released after they are acquired.

Would cause a memory leak otherwise.

Pull Request: https://projects.blender.org/blender/blender/pulls/107361

source/blender/io/usd/intern/usd_writer_material.cc

@@ -17,6 +17,7 @@
 #include "BLI_linklist.h"
 #include "BLI_listbase.h"
 #include "BLI_math.h"
+#include "BLI_memory_utils.hh"
 #include "BLI_path_util.h"
 #include "BLI_string.h"
 
@@ -378,6 +379,7 @@ static std::string get_in_memory_texture_filename(Image *ima)
 
   ImageFormatData imageFormat;
   BKE_image_format_from_imbuf(&imageFormat, imbuf);
+  BKE_image_release_ibuf(ima, imbuf, nullptr);
 
   char file_name[FILE_MAX];
   /* Use the image name for the file name. */
@@ -405,6 +407,7 @@ static void export_in_memory_texture(Image *ima,
   }
 
   ImBuf *imbuf = BKE_image_acquire_ibuf(ima, nullptr, nullptr);
+  BLI_SCOPED_DEFER([&]() { BKE_image_release_ibuf(ima, imbuf, nullptr); });
   if (!imbuf) {
     return;
   }