Fix for 5083973 M4VSS3GPP_editCleanUp called twice problem.

Set VSS context to NULL after cleanup.

Change-Id: I1086fbe60a7777b00e80f0ea504f58a183fd3241
diff --git a/libvideoeditor/vss/src/M4xVSS_internal.c b/libvideoeditor/vss/src/M4xVSS_internal.c
index e23e703..3827720 100755
--- a/libvideoeditor/vss/src/M4xVSS_internal.c
+++ b/libvideoeditor/vss/src/M4xVSS_internal.c
@@ -2348,6 +2348,9 @@
         M4OSA_TRACE1_1("M4xVSS_internalGenerateEditedFile: M4VSS3GPP_editInit returned 0x%x\n",
             err);
         M4VSS3GPP_editCleanUp(pVssCtxt);
+        /**
+         * Set the VSS context to NULL */
+        xVSS_context->pCurrentEditContext = M4OSA_NULL;
         return err;
     }
 
@@ -2508,6 +2511,9 @@
         M4OSA_TRACE1_1("M4xVSS_internalGenerateEditedFile:\
              M4VSS3GPP_editOpen returned 0x%x\n",err);
         M4VSS3GPP_editCleanUp(pVssCtxt);
+        /**
+         * Set the VSS context to NULL */
+        xVSS_context->pCurrentEditContext = M4OSA_NULL;
         return err;
     }
 
@@ -2546,12 +2552,18 @@
             M4OSA_TRACE1_1("M4xVSS_internalCloseEditedFile:\
                  M4VSS3GPP_editClose returned 0x%x\n",err);
             M4VSS3GPP_editCleanUp(pVssCtxt);
+            /**
+             * Set the VSS context to NULL */
+            xVSS_context->pCurrentEditContext = M4OSA_NULL;
             return err;
         }
 
         /**
          * Free this VSS3GPP edition instance */
         err = M4VSS3GPP_editCleanUp(pVssCtxt);
+        /**
+         * Set the VSS context to NULL */
+        xVSS_context->pCurrentEditContext = M4OSA_NULL;
         if (err != M4NO_ERROR)
         {
             M4OSA_TRACE1_1("M4xVSS_internalCloseEditedFile: \