Some compilers complained about using a value that depends on the input for the
size argument passed to `strncpy`. They missed that the size of `buf` also
depends on the source argument and therefore this use is fine.
```
CC src/utils/common/common_test.o
../../src/utils/common/common_test.c: In function 'test_parse_values':
../../src/utils/common/common_test.c:316:5: error: 'strncpy' specified bound depends on the length of the source argument [-Werror=stringop-overflow=]
316 | strncpy(buf, cases[i].buffer, buf_sz);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../src/utils/common/common_test.c:314:21: note: length computed here
314 | size_t buf_sz = strlen(cases[i].buffer) + 1;
| ^~~~~~~~~~~~~~~~~~~~~~~
```
size_t buf_sz = strlen(cases[i].buffer) + 1;
char buf[buf_sz];
- strncpy(buf, cases[i].buffer, buf_sz);
+ strncpy(buf, cases[i].buffer, sizeof(buf));
int status = parse_values(cases[i].buffer, &vl, &ds);
EXPECT_EQ_INT(cases[i].status, status);