Silent ASDF compiling output

[leovalais]

Hide output like:

; compiling file "/cl-lsystem/lsystem.lisp" (written 23 MAY 2019 08:58:10 PM):
; compiling (IN-PACKAGE :CL-LSYSTEM)
; compiling (DEFTYPE PARAMETRIZED-LETTER ...)
; compiling (DEFTYPE PARAMETRIZED-WORD ...)
; compiling (DEFCLASS RULE ...)
; compiling (DEFCLASS LSYSTEM ...)
; compiling (DEFGENERIC SET-RULE ...)
; compiling (DEFUN RULE-OF-PARAMETRIZED-LETTER ...)
; compiling (DEFUN PARAMETRIZED-LETTER->INSTRUCTION ...)
; compiling (DEFUN EXPAND-LETTER ...)
; compiling (DEFUN %ITER-LSYSTEM ...)
; compiling (DEFUN ITER-LSYSTEM ...)
; compiling (DEFPARAMETER *LSYSTEM* ...)
; compiling (DEFMACRO DEFINE-LSYSTEM ...)
; compiling (DEFMACRO DEFINE-RULE ...)
; compiling (DEFMACRO PARAMETRIC-WORD ...)
; compiling (DEFMACRO INSTRUCTION-CONSTRUCTOR ...)
; compiling (SET-DISPATCH-MACRO-CHARACTER #\# ...)
; compiling (SET-DISPATCH-MACRO-CHARACTER #\# ...)

; wrote /root/.cache/common-lisp/sbcl-1.4.13-linux-x64/cl-lsystem/lsystem-tmp5GEXGEG5.fasl
; compilation finished in 0:00:00.051