Fix -Wstringop-overflow warnings in drivers/net/wireless/realtek/rtw89/coex.c

[GustavoARSilva]

Found in x86_64

drivers/net/wireless/realtek/rtw89/coex.c: In function '_append_tdma':
include/linux/fortify-string.h:57:33: warning: writing 8 bytes into a region of size 0 [-Wstringop-overflow=]
   57 | #define __underlying_memcpy     __builtin_memcpy
      |                                 ^
include/linux/fortify-string.h:648:9: note: in expansion of macro '__underlying_memcpy'
  648 |         __underlying_##op(p, q, __fortify_size);                        \
      |         ^~~~~~~~~~~~~
include/linux/fortify-string.h:693:26: note: in expansion of macro '__fortify_memcpy_chk'
  693 | #define memcpy(p, q, s)  __fortify_memcpy_chk(p, q, s,                  \
      |                          ^~~~~~~~~~~~~~~~~~~~
drivers/net/wireless/realtek/rtw89/coex.c:1585:17: note: in expansion of macro 'memcpy'
 1585 |                 memcpy(&v3->tdma, &dm->tdma, sizeof(v3->tdma));
      |                 ^~~~~~
drivers/net/wireless/realtek/rtw89/core.h:2428:37: note: at offset [5714, 71249] into destination object 'ver' of size 8
 2428 |         const struct rtw89_btc_ver *ver;
      |                                     ^~~
include/linux/fortify-string.h:57:33: warning: writing 8 bytes into a region of size 0 [-Wstringop-overflow=]
   57 | #define __underlying_memcpy     __builtin_memcpy
      |                                 ^
include/linux/fortify-string.h:648:9: note: in expansion of macro '__underlying_memcpy'
  648 |         __underlying_##op(p, q, __fortify_size);                        \
      |         ^~~~~~~~~~~~~
include/linux/fortify-string.h:693:26: note: in expansion of macro '__fortify_memcpy_chk'
  693 | #define memcpy(p, q, s)  __fortify_memcpy_chk(p, q, s,                  \
      |                          ^~~~~~~~~~~~~~~~~~~~
drivers/net/wireless/realtek/rtw89/coex.c:1579:17: note: in expansion of macro 'memcpy'
 1579 |                 memcpy(v, &dm->tdma, sizeof(*v));
      |                 ^~~~~~
drivers/net/wireless/realtek/rtw89/core.h:2428:37: note: at offset [5710, 71245] into destination object 'ver' of size 8
 2428 |         const struct rtw89_btc_ver *ver;
      |                                     ^~~