tests: drivers: can: timing: do not overwrite sample point error value
tests: drivers: can: timing: do not overwrite sample point error value

Do not overwrite the sample point error value as it is printed at the
very end of the test.

Fixes: 578454b78d3e425f7d654233b47cbc25d7484f92

Signed-off-by: Henrik Brix Andersen <24a3f13c22635bab658e39fc5f1e63c575328aae@vestas.com>

galak/zephyr,galak/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,galak/zephyr