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>
(transplanted from f070d922facf42b0395b7db909e1867d45b245dd)

 # dmalloc debug facility

 ## depends on ! BACKEND

 ##

 ## help dmalloc helps tracking memory allocation mis-usage

 ## help such as double-free, use-after-free...

 choice

     bool

     prompt "dmalloc version"

 # Don't remove next line

 # CT_INSERT_VERSION_BELOW

 config DMALLOC_V_5_5_2

     bool

     prompt "5.5.2"

 endchoice

 config DMALLOC_VERSION

     string

 # Don't remove next line

 # CT_INSERT_VERSION_STRING_BELOW

     default "5.5.2" if DMALLOC_V_5_5_2