buildroot

package/pkg-golang: drop the fixed <pkg>_BINDIR variable

Now that <pkg>_BINDIR is always "bin", having it as a package variable
doesn't make much sense, so get rid of this variable completely, and
use "bin".

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Reviewed-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>