cmd/search: --desc depends on --eval-all, not the other way around

- When the user tried `brew search foo` with `--eval-all` or its
  envvar, it would fail with
  `Error: Invalid usage: `--eval-all` cannot be passed without `--desc`.`
- This was the wrong way around: `--desc` depends on `--eval-all`.

Author: issyl0

Library/Homebrew/cmd/search.rb

@@ -36,9 +36,9 @@ class SearchCmd < AbstractCommand
                description: "Search for casks."
         switch "--desc",
                description: "Search for formulae with a description matching <text> and casks with " \
-                            "a name or description matching <text>."
+                            "a name or description matching <text>.",
+               depends_on:  "--eval-all"
         switch "--eval-all",
-               depends_on:  "--desc",
                description: "Evaluate all available formulae and casks, whether installed or not, to search their " \
                             "descriptions.",
                env:         :eval_all