GCC 14 introduces a new -Walloc-size included in -Wextra which gives:
```
src/tool_operate.c: In function ‘add_per_transfer’:
src/tool_operate.c:213:5: warning: allocation of insufficient size ‘1’ for type ‘struct per_transfer’ with size ‘480’ [-Walloc-size]
213 | p = calloc(sizeof(struct per_transfer), 1);
| ^
src/var.c: In function ‘addvariable’:
src/var.c:361:5: warning: allocation of insufficient size ‘1’ for type ‘struct var’ with size ‘32’ [-Walloc-size]
361 | p = calloc(sizeof(struct var), 1);
| ^
```
The calloc prototype is:
```
void *calloc(size_t nmemb, size_t size);
```
So, just swap the number of members and size arguments to match the
prototype, as we're initialising 1 struct of size `sizeof(struct
...)`. GCC then sees we're not doing anything wrong.
Closes#12292
bc8509a748