SG_SET_TIMEOUT 0x2201. Assumes 3rd argument points to an int containing the new timeout value
for this file descriptor. The unit is a "jiffy". Packets that are
already "in flight" will not be affected. The default value is set
on open() and is SG_DEFAULT_TIMEOUT (defined in sg.h). This default is
currently 1 minute and may not be long enough for formats. Negative
values will yield an EIO error.
This ioctl() is not relevant to the sg version 3 driver because timeouts
are specified explicitly for each command in the sg_io_hdr structure.
Only when the sg_header structure is used is the timeout inherited from
this value (help on a per file descriptor basis).