[nemo-qtmultimedia-plugins] Fixed memory leak in NemoVideoTextureBack…

…end::probe. Fixes JB#41824

==25456== 10 bytes in 1 blocks are definitely lost in loss record 1,852 of 8,690
==25456==    at 0x483F3EC: malloc (vg_replace_malloc.c:299)
==25456==    by 0x5AF00DF: g_malloc (gmem.c:94)
==25456==    by 0x5B07185: g_strdup (gstrfuncs.c:363)
==25456==    by 0xF38F143: _gst_strdup0 (gsttaglist.c:1762)
==25456==    by 0xF38F143: gst_tag_list_get_string (gsttaglist.c:1808)
==25456==    by 0x102274B7: NemoVideoTextureBackend::probe(_GstPad*, _GstPadProbeInfo*, void*) (videotexturebackend.cpp:799)

src/videotexturebackend/videotexturebackend.cpp

@@ -807,6 +807,8 @@ GstPadProbeReturn NemoVideoTextureBackend::probe(GstPad *, GstPadProbeInfo *info
         } else {
             orientation = 0;
         }
+
+        g_free(orientationTag);
     } else if (GST_EVENT_TYPE(event) == GST_EVENT_STREAM_START) {
         orientation = 0;
     }