fix unused return types in nv_dds.cpp

src/nv_dds/nv_dds.cpp

@@ -302,7 +302,7 @@ bool CDDSImage::load(string filename, bool flipImage)
 
     // read in file marker, make sure its a DDS file
     char filecode[4];
-    fread(filecode, 1, 4, fp);
+    (void)fread(filecode, 1, 4, fp);
     if (strncmp(filecode, "DDS ", 4) != 0)
     {
         fclose(fp);
@@ -311,7 +311,7 @@ bool CDDSImage::load(string filename, bool flipImage)
 
     // read in DDS header
     DDS_HEADER ddsh;
-    fread(&ddsh, sizeof(DDS_HEADER), 1, fp);
+    (void)fread(&ddsh, sizeof(DDS_HEADER), 1, fp);
 
     swap_endian(&ddsh.dwSize);
     swap_endian(&ddsh.dwFlags);
@@ -410,7 +410,7 @@ bool CDDSImage::load(string filename, bool flipImage)
 
         // load surface
         unsigned char *pixels = new unsigned char[size];
-        fread(pixels, 1, size, fp);
+        (void)fread(pixels, 1, size, fp);
 
         img.create(width, height, depth, size, pixels);
         
@@ -443,7 +443,7 @@ bool CDDSImage::load(string filename, bool flipImage)
             size = (this->*sizefunc)(w, h)*d;
 
             unsigned char *pixels = new unsigned char[size];
-            fread(pixels, 1, size, fp);
+            (void)fread(pixels, 1, size, fp);
 
             mipmap.create(w, h, d, size, pixels);