[bug report] selftests, arm64: add a selftest for passing tagged pointers to kernel

[Dan Carpenter <dan.carpenter@oracle.com>]

Hello Andrey Konovalov,

The patch 9ce1263033cd: "selftests, arm64: add a selftest for passing
tagged pointers to kernel" from Jul 23, 2019, leads to the following
static checker warning:

	./tools/testing/selftests/arm64/tags_test.c:25 main()
	error: uninitialized symbol 'tagged_ptr'.

tools/testing/selftests/arm64/tags_test.c
    14  int main(void)
    15  {
    16          static int tbi_enabled = 0;
    17          struct utsname *ptr, *tagged_ptr;
                                      ^^^^^^^^^^

    18          int err;
    19  
    20          if (prctl(PR_SET_TAGGED_ADDR_CTRL, PR_TAGGED_ADDR_ENABLE, 0, 0, 0) == 0)
    21                  tbi_enabled = 1;
    22          ptr = (struct utsname *)malloc(sizeof(*ptr));
    23          if (tbi_enabled)
    24                  tagged_ptr = (struct utsname *)SET_TAG(ptr, 0x42);
                ^^^^^^^^^^^^^^^
No else path.

    25          err = uname(tagged_ptr);
    26          free(ptr);
    27  
    28          return err;
    29  }

regards,
dan carpenter