Fix crash when scanning corrupt midi file.

b/5453816

Change-Id: Ic2104fc0b86ef0b5ec3af7a009b193f85690d291
diff --git a/arm-wt-22k/lib_src/eas_smf.c b/arm-wt-22k/lib_src/eas_smf.c
index 9e096b6..7b0bdd8 100644
--- a/arm-wt-22k/lib_src/eas_smf.c
+++ b/arm-wt-22k/lib_src/eas_smf.c
@@ -281,6 +281,11 @@
     if (pSMFData->state >= EAS_STATE_OPEN)
         return EAS_SUCCESS;
 
+    if (!pSMFData->nextStream) {
+        return EAS_ERROR_FILE_FORMAT;
+    }
+
+
     /* get current ticks */
     ticks = pSMFData->nextStream->ticks;