wireless/wapi/src/wapi.c: When executing a command return it's error code on failure.

Signed-off-by: Abdelatif Guettouche <abdelatif.guettouche@espressif.com>
diff --git a/wireless/wapi/src/wapi.c b/wireless/wapi/src/wapi.c
index cc8c28f..13d717b 100644
--- a/wireless/wapi/src/wapi.c
+++ b/wireless/wapi/src/wapi.c
@@ -1021,6 +1021,7 @@
   FAR const struct wapi_command_s *wapicmd;
   int sock;
   int i;
+  int ret;
 
   /* Get the command */
 
@@ -1080,7 +1081,8 @@
       return EXIT_FAILURE;
     }
 
-  if (wapicmd->handler(sock, argc - 2, argc == 2 ? NULL : &argv[2]) < 0)
+  ret = wapicmd->handler(sock, argc - 2, argc == 2 ? NULL : &argv[2]);
+  if (ret < 0)
     {
       WAPI_ERROR("ERROR: Process command (%s) failed.\n", cmdname);
     }
@@ -1088,5 +1090,5 @@
   /* Close communication socket */
 
   close(sock);
-  return EXIT_SUCCESS;
+  return ret;
 }