apps/system/vi: Add missing vi_release before exit.

If VI exit without vi_release, that broken console.

Signed-off-by: Leo Chung <gewalalb@gmail.com>

system/vi/vi.c

@@ -559,6 +559,7 @@ static void vi_write(FAR struct vi_s *vi, FAR const char *buffer,
             {
               fprintf(stderr, "ERROR: write to stdout failed: %d\n",
                       errcode);
+              vi_release(vi);
               exit(EXIT_FAILURE);
             }
         }
@@ -635,6 +636,7 @@ static int vi_getch(FAR struct vi_s *vi)
                 {
                   fprintf(stderr, "ERROR: read from stdin failed: %d\n",
                           errcode);
+                  vi_release(vi);
                   exit(EXIT_FAILURE);
                 }
             }