core: rpc core.psx is returning an array

- otherwise it breaks unique member name for structures, because it
  returs many records

core_cmd.c

@@ -969,7 +969,7 @@ static rpc_export_t core_rpc_methods[] = {
 		0        },
 	{"core.uptime",            core_uptime,            core_uptime_doc,            0        },
 	{"core.ps",                core_ps,                core_ps_doc,                RET_ARRAY},
-	{"core.psx",               core_psx,               core_psx_doc,                0},
+	{"core.psx",               core_psx,               core_psx_doc,               RET_ARRAY},
 	{"core.pwd",               core_pwd,               core_pwd_doc,               RET_ARRAY},
 	{"core.arg",               core_arg,               core_arg_doc,               RET_ARRAY},
 	{"core.kill",              core_kill,              core_kill_doc,              0        },