tests/kernel/mem_pool/mem_pool_concept/testcase.yaml#kernel.memory_pool fails on nrf52840_pca10056, nrf52_pca10040 and nrf51_pca10028

[spoorthik]

Execution log:

Running test suite mpool_concept
===================================================================
starting test - test_mpool_alloc_wait_prio

    Assertion failed at /home/kspoorth/work/latest_zephyr/tests/kernel/mem_pool/mem_pool_concept/src/test_mpool_alloc_wait.c:24: tmpool_alloc_wait_timeout: k_mem_pool_alloc(&mpool1, &block, BLK_SIZE_MIN, TIMEOUT) == -EAGAIN is false

FAIL - test_mpool_alloc_wait_prio
===================================================================
starting test - test_mpool_alloc_size_roundup

    Assertion failed at /home/kspoorth/work/latest_zephyr/tests/kernel/mem_pool/mem_pool_concept/src/test_mpool_alloc_size.c:36: test_mpool_alloc_size_roundup: k_mem_pool_alloc(&mpool1, &block[i], TEST_SIZE, K_NO_WAIT) == 0 is false

FAIL - test_mpool_alloc_size_roundup
===================================================================
starting test - test_mpool_alloc_merge_failed_diff_size
PASS - test_mpool_alloc_merge_failed_diff_size
===================================================================
starting test - test_mpool_alloc_merge_failed_diff_parent

    Assertion failed at /home/kspoorth/work/latest_zephyr/tests/kernel/mem_pool/mem_pool_concept/src/test_mpool_merge_fail_diff_parent.c:33: test_mpool_alloc_merge_failed_diff_parent: k_mem_pool_alloc(&mpool1, &block[i], BLK_SIZE_MIN, K_NO_WAIT) == 0 is false

FAIL - test_mpool_alloc_merge_failed_diff_parent
===================================================================
===================================================================
PROJECT EXECUTION FAILED

Steps to reproduce:
cd tests/kernel/mem_pool/mem_pool_concept
mkdir build && cd build
cmake -DBOARD=nrf51_pca10028 .. && make flash

Latest commit: afa0e00

Platforms tested: nrf52840_pca10056, nrf52_pca10040 and nrf51_pca10028

[nashif]

bisected to 3c7f990

commit 3c7f990367f38c84b20e7888042ea9429cfae8a6
Author: Piotr Zięcik <piotr.ziecik@nordicsemi.no>
Date:   Mon Jul 23 14:09:10 2018 +0200

    kernel: Do not use sys_clock_ticks_per_sec in _ms_to_ticks()

    The value of sys_clock_ticks_per_sec is obtained using
    simple integer division with rounding toward zero. As result
    using this variable in _ms_to_ticks() introduces some error.

    This commit eliminates sys_clock_ticks_per_sec from equation
    used in _ms_to_ticks() removing introduced error.

    Also, this commit fixes #8895.

    Signed-off-by: Piotr Zięcik <piotr.ziecik@nordicsemi.no>

[nashif]

@carlescufi fyi

[carlescufi]

@ioannisg fyi, let's take a look at this together