Add negative test case for CheckPasswordHashUnix #224

Job	Run time
Build wolfSSL (v5.8.4-stable)	3s
Build OpenSSH	5s
Build wolfSSL (master)	4s
Build and test wolfSSH (master)	26s
Build and test wolfSSH (v5.8.4-stable, --enable-smallstack)	27s
Build and test wolfSSH (v5.8.4-stable)	36s
Build and test wolfSSH (master, --enable-smallstack)	26s
	2m 7s

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