scripts/functions: force extract folder to archive basename

Some archives like those of the 2011.07 revisions of Linaro GCC contain a folder
name different from the archive basename, which leads to errors afterwards, e.g.
when patching. E.g.:
gcc-linaro-4.5-2011.07.tar.bz2 extracts to gcc-linaro-4.5-2011.07-0/

This patch changes CT_Extract() to force the extraction of all archives to a
folder named like the archive basename. E.g.:
gcc-linaro-4.5-2011.07.tar.bz2 now extracts to gcc-linaro-4.5-2011.07/

Signed-off-by: "Benoît THÉBAUDEAU" <benoit.thebaudeau@advansee.com>

 # Super-H specific configuration file

 ## select ARCH_SUPPORTS_32

 ## select ARCH_DEFAULT_32

 ## select ARCH_USE_MMU

 ## select ARCH_SUPPORTS_BOTH_ENDIAN

 ## select ARCH_DEFAULT_LE

 ##

 ## help The Super-H architecture, as defined by:

 ## help     http://www.renesas.com/fmwk.jsp?cnt=superh_family_landing.jsp&fp=/products/mpumcu/superh_family/