complibs: fix using static companion libraries

When building a cross-compiler for a target which uses a file extension for
binaries the symbolic link to cc is not created correctly because the lookup
of the gcc binary is done in a incorrect path

Signed-off-by: Bart vdr. Meulen <bartvdrmeulen@gmail.com>

 # Compute M68k-specific values

 CT_DoArchTupleValues() {

     :

 }