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>

# Options specific to crosstool-NG acting as a backend

config IS_A_BACKEND

    string

    option env="CT_IS_A_BACKEND"

config BACKEND

    bool

    default y if IS_A_BACKEND =  "y" || IS_A_BACKEND =  "Y"

    default n if IS_A_BACKEND != "y" && IS_A_BACKEND != "Y"

config BACKEND_ARCH

    string

    option env="CT_BACKEND_ARCH"

config BACKEND_KERNEL

    string

    option env="CT_BACKEND_KERNEL"

config BACKEND_LIBC

    string

    option env="CT_BACKEND_LIBC"