StarPU: Use character _ instead of - in filenames

configure.ac

@@ -57,7 +57,7 @@ AC_SUBST(STARPU_DIR, $PWD)
 
 AC_CHECK_LIB([pthread], [pthread_create])
 case "$target" in
-*-*-mingw*) CPPFLAGS+=" -I$PWD/include/pthread-win32 " ;;
+*-*-mingw*) CPPFLAGS+=" -I$PWD/include/pthread_win32 " ;;
 esac
 AC_COMPILE_IFELSE(
   AC_LANG_PROGRAM([[