linux(4): Properly allocate buffer for kern_getdirentries in readdir
Looks like prior to ino64 project the size of the struct linux_dirent
was greater (or equal) to the size of the native struct dirent so the
native dirent fit into the buffer. After ino64 project the size of the
native struct dirent has increased.
Spotted by gcc12.
MFC after: 2 weeks
(cherry picked from commit fc1c787aa0157090e765ebba484e6e290e99f177)