Merge pull request #676 from erhankur/fix/riscv_remove_trigger_return_code

riscv: fix remove_trigger return code for unavailable hw bp slot

src/target/riscv/riscv.c

@@ -927,7 +927,7 @@ static int remove_trigger(struct target *target, struct trigger *trigger)
 	if (i >= r->trigger_count) {
 		LOG_ERROR("Couldn't find the hardware resources used by hardware "
 				"trigger.");
-		return ERROR_FAIL;
+		return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
 	}
 	LOG_DEBUG("[%d] Stop using resource %d for bp %d", target->coreid, i,
 			trigger->unique_id);