mach.rb: remove incorrect comment

IO#read does not raise EOFError, it just returns an empty string for
each call after it consumes the underlying file or stream.

This module is going to be refactored and the begin/rescue is going to
be removed anyway.

Library/Homebrew/mach.rb

@@ -66,9 +66,6 @@ module MachO
       end
       mach_data
     rescue
-      # read() will raise if it sees EOF, which should only happen if the
-      # file is < 8 bytes. Otherwise, we raise if the file is not a Mach-O 
-      # binary. In both cases, we want to return an empty array.
       []
     end
   end