Flush the debug message out to the log file.

This patch fluesh the debug messages to the log file  at the end of each
debug message.

Changes from V1:
Used fflush instead fseek for the flush.
Signed-off-by: NVenkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

hw/virtio-9p-debug.c

@@ -481,4 +481,6 @@ void pprint_pdu(V9fsPDU *pdu)
     }
 
     fprintf(llogfile, ")\n");
+    /* Flush the log message out */
+    fflush(llogfile);
 }