tests: ztest: fix board name

Use full board name in cmake file.

Signed-off-by: Anas Nashif <[email protected]>

Author: nashif

tests/ztest/zexpect/CMakeLists.txt

@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: Apache-2.0
 
 cmake_minimum_required(VERSION 3.20.0)
-if(BOARD STREQUAL unit_testing)
+if(BOARD STREQUAL unit_testing/unit_testing)
   find_package(Zephyr COMPONENTS unittest REQUIRED HINTS $ENV{ZEPHYR_BASE})
   project(base)