enumerate all formulae by files rather than names

Before
```
$ time brew readall
brew readall  10.63s user 0.36s system 99% cpu 11.003 total
```

After
```
$ time brew readall
brew readall  5.62s user 0.24s system 99% cpu 5.859 total
```

Closes Homebrew/homebrew#42302.

Signed-off-by: Xu Cheng <xucheng@me.com>

1 files changed, 4 insertions, 4 deletions

diff --git a/Library/Homebrew/cmd/readall.rb b/Library/Homebrew/cmd/readall.rb
index 0714c18b1..a89b700f9 100644
--- a/Library/Homebrew/cmd/readall.rb
+++ b/Library/Homebrew/cmd/readall.rb
@@ -32,18 +32,18 @@ module Homebrew
 
     formulae = []
     if ARGV.named.empty?
-      formulae = Formula.full_names
+      formulae = Formula.files
     else
       tap = Tap.new(*tap_args)
       raise TapUnavailableError, tap.name unless tap.installed?
       formulae = tap.formula_files
     end
 
-    formulae.sort.each do |n|
+    formulae.each do |file|
       begin
-        Formulary.factory(n)
+        Formulary.factory(file)
       rescue Exception => e
-        onoe "problem in #{Formulary.path(n)}"
+        onoe "problem in #{file}"
         puts e
         Homebrew.failed = true
       end