[SYCLomatic] Fix malloc memory size bug of math half2 tests. #2056

Job	Run time
linux-test-user_guide_samples-cpu	6m 50s
linux-test-regressions-cpu	14m 39s
linux-test-samples-cpu	12m 35s
linux-test-help_function-cpu	32m 45s
linux-test-features-cpu	22m 32s
linux-test-api_coverage-cpu	7m 37s
linux-test-behavior_tests-cpu	8m 35s
linux-test-applications-cpu	9m 34s
	1h 55m 7s

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