functions: avoid CR when progress bar is not enabled

Using CT-NG with progress bar disabled, still prints CR ('\r') characters
on the output. When you capture the output to a file as part of an
automated build, it shows extra empty lines.

For example:

------------------------------------------------------------
[INFO ] Performing some trivial sanity checks

[INFO ] Build started 20110404.113619

[INFO ] Building environment variables

[EXTRA] Preparing working directories

[EXTRA] Installing user-supplied crosstool-NG configuration
------------------------------------------------------------

Signed-off-by: Javier Viguera <javier.viguera@digi.com>
(transplanted from cbd07f3dd6e3689a6b971e999aa82d09fb94d515)

1.10.0+hg