libc/(e)glibc: fix extra configparms

In case ${CT_LIBC_GLIBC_CONFIGPARMS} starts with a dash, printf will try
to interpret it as an option for itself, and will invariably flail in
panic as it does not recognise any of it.

Use a more robust solution, as suggested by Cody.

Reported-by: "Roberto A. Foglietta" <roberto.foglietta@gmail.com>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Cody P Schafer <devel-lists@codyps.com>

CT_EXPERIMENTAL=y

CT_LOCAL_TARBALLS_DIR="${HOME}/src"

CT_SAVE_TARBALLS=y

CT_LOG_EXTRA=y

CT_ARCH_s390=y

CT_KERNEL_linux=y

CT_KERNEL_V_2_6_31=y

CT_BINUTILS_V_2_20_1a=y

CT_CC_V_4_3_4=y

CT_CC_LANG_CXX=y

CT_LIBC_glibc=y

CT_LIBC_GLIBC_V_2_9=y

CT_GMP_V_4_3_2=y

CT_MPFR_V_2_4_2=y