Switch perl to logging

To find the users and see if we can get rid of it.

Test: treehugger
Change-Id: I149f8daee6e21b35840ea1788de7f3e310eb5fba

ui/build/paths/config.go

@@ -39,6 +39,12 @@ var Forbidden = PathConfig{
 	Error:   true,
 }
 
+var Log = PathConfig{
+	Symlink: true,
+	Log: true,
+	Error: false,
+}
+
 // The configuration used if the tool is not listed in the config below.
 // Currently this will create the symlink, but log and error when it's used. In
 // the future, I expect the symlink to be removed, and this will be equivalent
@@ -104,7 +110,7 @@ var Configuration = map[string]PathConfig{
 	"openssl":   Allowed,
 	"paste":     Allowed,
 	"patch":     Allowed,
-	"perl":      Allowed,
+	"perl":      Log,
 	"pgrep":     Allowed,
 	"pkill":     Allowed,
 	"ps":        Allowed,