lib/hashtable.c: don't test ->callback in SPL

In SPL, environment callbacks are not supported, so e->callback is
always NULL. Removing this makes the SPL a little smaller (about 400
bytes in my ppc build) with no functional change.

Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Reviewed-by: Simon Glass <sjg@chromium.org>
1 file changed