Fix #64, add CFE_SB_InitMsg() for housekeeping UT (HOTFIX)

The FSW code relies on the message being pre-initalized which
needs to be done explicitly in unit test code.

unit-test/coveragetest/coveragetest_sample_app.c

@@ -375,6 +375,18 @@ void Test_SAMPLE_ReportHousekeeping(void)
     SAMPLE_AppData.CmdCounter = 22;
     SAMPLE_AppData.ErrCounter = 11;
 
+    /*
+     * CFE_SB_InitMsg() needs to be done to set the emulated MsgId and Length.
+     *
+     * The FSW code only does this once during init and relies on it
+     * remaining during the SAMPLE_ReportHousekeeping().  This does
+     * not happen during UT so it must be initialized again here.
+     */
+    CFE_SB_InitMsg(&SAMPLE_AppData.HkBuf.MsgHdr,
+                   SAMPLE_APP_HK_TLM_MID,
+                   sizeof(SAMPLE_AppData.HkBuf),
+                   true);
+
     /*
      * Set up to "capture" the telemetry message
      */