keg_relocate: don't assume .la files are in lib.

Sometimes they are in e.g. libexec but there's no real reason to assume
they are anywhere; we want to relocate them regardless.

Library/Homebrew/keg_relocate.rb

@@ -183,11 +183,10 @@ class Keg
   def libtool_files
     libtool_files = []
 
-    # find .la files, which are stored in lib/
-    lib.find do |pn|
+    path.find do |pn|
       next if pn.symlink? || pn.directory? || pn.extname != ".la"
       libtool_files << pn
-    end if lib.directory?
+    end
     libtool_files
   end