vlib: fix vlib_log for elog

test output before fix:
DBGvpp# event-logger clear
DBGvpp# test log warn cli log test-log for-elog
cli/log            [warn  ]: test-log for-elog
DBGvpp# test log info cli log test-log for-elog
cli/log            [info  ]: test-log for-elog
DBGvpp# show event-logger
2 of 131072 events in buffer, logger running
      53.022586433: log-notice: test-log for-elog
      60.318329361: log-debug: test-log for-elog
DBGvpp#

test output after fix:
DBGvpp# event-logger clear
DBGvpp# test log warn cli log test-log for-elog
cli/log            [warn  ]: test-log for-elog
DBGvpp# test log info cli log test-log for-elog
cli/log            [info  ]: test-log for-elog
DBGvpp# show event-logger
2 of 131072 events in buffer, logger running
      18.362721151: log-warn: test-log for-elog
      25.124570555: log-info: test-log for-elog
DBGvpp#

Type: fix

Signed-off-by: luoyaozu <luoyaozu@foxmail.com>
Change-Id: Ie1122787f9efb611cdafc671b4ccf68b43984924
diff --git a/src/vlib/log.c b/src/vlib/log.c
index d084511..f176062 100644
--- a/src/vlib/log.c
+++ b/src/vlib/log.c
@@ -226,13 +226,13 @@
 
       if (lm->add_to_elog)
 	{
-          /* *INDENT-OFF* */
-          ELOG_TYPE_DECLARE(ee) =
+	  ELOG_TYPE_DECLARE(ee) =
             {
              .format = "log-%s: %s",
              .format_args = "t4T4",
-             .n_enum_strings = 9,
+             .n_enum_strings = VLIB_LOG_N_LEVELS,
              .enum_strings = {
+                "unknown",
                 "emerg",
                 "alert",
                 "crit",
@@ -244,11 +244,11 @@
                 "disabled",
                 },
             };
-          struct {
-            u32 log_level;
-            u32 string_index;
-          } *ed;
-          /* *INDENT-ON* */
+	  struct
+	  {
+	    u32 log_level;
+	    u32 string_index;
+	  } * ed;
 	  ed = ELOG_DATA (&vlib_global_main.elog_main, ee);
 	  ed->log_level = level;
 	  ed->string_index =