tests/pack: fixup 6774b107

Initialize the hash ctx with git_hash_ctx_init, not git_hash_init.

tests-clar/pack/packbuilder.c

@@ -106,9 +106,10 @@ void test_pack_packbuilder__create_pack(void)
 
 	cl_git_pass(git_futils_readbuffer(&buf, "testpack.pack"));
 
-	cl_git_pass(git_hash_init(&ctx));
+	cl_git_pass(git_hash_ctx_init(&ctx));
 	cl_git_pass(git_hash_update(&ctx, buf.ptr, buf.size));
 	cl_git_pass(git_hash_final(&hash, &ctx));
+	git_hash_ctx_cleanup(&ctx);
 
 	git_buf_free(&buf);