isobusfs_srv_cm: stringop-overflow

[marckleinebudde]

build for amd64 with:

mkdir debug
cd debug
cmake -DCMAKE_BUILD_TYPE=Debug ..
make

isobusfs/isobusfs_srv_cm.c: In function ‘isobusfs_srv_volume_status_resp’:                                                                                                                             
isobusfs/isobusfs_srv_cm.c:577:17: warning: ‘memset’ specified size 18446744073709551364 exceeds maximum object size 9223372036854775807 [-Wstringop-overflow=]                                        
  577 |                 memset(((uint8_t *) &resp) + sizeof(resp), 0xFF, buf_size - sizeof(resp));                                                                                                                                                              
      |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~                                                                                                                                                               
isobusfs/isobusfs_srv_cm.c:563:41: note: destination object allocated here                                                                                                                             
  563 |         struct isobusfs_cm_vol_stat_res resp = {0};                                                                                                                                                                                                     
      |                                         ^~~~                               

[marckleinebudde]

Closed with https://github.com/linux-can/can-utils/pull/530