Stop echo from swallowing passthrough arguments

The job expansion wrapper was swallowing `-n` (and presumably `-e` and
others) when that was the literal argument we needed to emit. Using
`printf %s ...` instead.

share/config.fish

@@ -268,7 +268,7 @@ function __fish_expand_pid_args
                 return 1
             end
         else
-            echo $arg
+            printf "%s\n" $arg
         end
     end
 end