cc/gcc: fix building core when building statically

There was a mishap when cut-n-pasting code from the final
step into the core step: a variable was not renamed.

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

reporter_name="Bart vdr. Meulen <bartvdrmeulen@gmail.com>"

reporter_url=""

reporter_comment="Config to build cross-compiler with mingw as kernel type"