"BIG" in the name refers to the amount of data being transferred, _not_ the
size of structure itself; it's 140 or 144 bytes (for 32bit and 64bit hosts
resp.).  IOCTL_Command_struct is 136 or 144 bytes large...

No point whatsoever turning that into dynamic allocation, let alone vmalloc
one.  Just keep it as local variable...

Link: https://lore.kernel.org/r/20200529234028.46373-2-viro@ZenIV.linux.org.ukAcked-by: NDon Brace <don.brace@microsemi.com>
Tested-by: NDon Brace <don.brace@microsemi.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>