complibs/cloog: fix extraction

In the early days, cloog-ppl was bizarrely packaged: the first tarball
did not contain the version in the name of the extracted directory, so
we had to play tricks.

Nowadays, however, the first component of the path are stripped when
extracting a tarball, which means that the created directory will
always be properly named. So, our old tricks do no longer work, and
worse, they break the build.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>

 # Menu for the native GDB

 config GDB_NATIVE

     bool

     prompt "Native gdb"

     depends on ! BARE_METAL

     depends on ! BACKEND

     help

       Build and install a native gdb for the target, to run on the target.

 if GDB_NATIVE

 config GDB_NATIVE_STATIC

     bool

     prompt "Build a static native gdb"

     help

       In case you have trouble with dynamic loading of shared libraries,

       you will find that a static gdb comes in handy.

 endif # GDB_NATIVE