(zilch file): fix unneccessary double-serialization in zfile

Change-Id: I6a6a69640707ff155f425f05aa857f03bad2650d

core/src/file.sld

@@ -197,20 +197,7 @@
          ((z-symlink? val) (z-symlink-cache val))))
      (unless cached
       (set! cached
-       (let*
-        ((bvport (open-output-bytevector))
-         (serialized (zexp-with-context (lambda () (parameterize ((current-output-port bvport)) (serialize-as-tar val "-")))))
-         (bv (get-output-bytevector bvport))
-         (intermediate #f)
-         (drv #f))
-        (close-port bvport)
-        ;(set! intermediate
-        ;  (zexp-with-injected-context
-        ;     (zexp
-        ;        (zexp-unquote (store-path-for-text "file" bv)))
-        ;     (cadr serialized)
-        ;     (car (cddr serialized))))
-        (set! drv
+       (cdar
         (store-path-for-ca-drv* "zilchfile" "builtin"
           (zexp ("builtin:unpack-channel"))
           (zexp (("src" . ".attr-1s42g1c76fxb77skzq0b4wdhcrg8jmzb54czmxvh1qm7psgsbcni")
@@ -218,8 +205,7 @@
                  ("passAsFile" . "contents")
                  ("allowSubstitutes" . "")
                  ("channelName" . "-")))
-            '("out")))
-        (cdar drv))))
+          '("out")))))
      (cond
        ((z-file? val) (z-file-set-cache val cached))
        ((z-directory? val) (z-directory-set-cache val cached))