bootloader: De-monadify configuration file generators.

* gnu/bootloader/extlinux.scm: Remove unneeded imports.
(extlinux-configuration-file): Use 'computed-file' instead of
'gexp->derivation'.
* gnu/bootloader/grub.scm (svg->png): Likewise.
(grub-background-image, eye-candy): Adjust accordingly, return
non-monadically.
(grub-configuration-file): Likewise, and use 'computed-file' instead of
'gexp->derivation'.
* gnu/bootloader/u-boot.scm: Remove unneeded imports.
* gnu/system.scm: Add 'lower-object' call.

1 files changed, 1 insertions, 5 deletions

diff --git a/gnu/bootloader/extlinux.scm b/gnu/bootloader/extlinux.scm
index 8b7a95a6fc4..b48596c4969 100644
--- a/gnu/bootloader/extlinux.scm
+++ b/gnu/bootloader/extlinux.scm
@@ -19,12 +19,8 @@
 
 (define-module (gnu bootloader extlinux)
   #:use-module (gnu bootloader)
-  #:use-module (gnu system)
-  #:use-module (gnu build bootloader)
   #:use-module (gnu packages bootloaders)
   #:use-module (guix gexp)
-  #:use-module (guix monads)
-  #:use-module (guix records)
   #:use-module (guix utils)
   #:export (extlinux-bootloader
             extlinux-bootloader-gpt))
@@ -78,7 +74,7 @@ TIMEOUT ~a~%"
                       (format port "~%"))
                    #~())))))
 
-  (gexp->derivation "extlinux.conf" builder))
+  (computed-file "extlinux.conf" builder))