FROMLIST: fuse: Allocate unlikely used ioctl number for passthrough V1

The current UAPI interface for FUSE passthrough is still under
discussion upstream, thus we are reserving this ioctl number to avoid
future conflicts with user space binaries.
The user space implementation in Android will take care of doing all the
checking to fall into the most appropriate ioctl number.

Bug: 167695973
Link: https://lore.kernel.org/lkml/20210125153057.3623715-3-balsini@android.com/


Fixes: abbb00d5 ("FROMLIST: fuse: Definitions and ioctl for passthrough")
Test: manual test with additional printks
Signed-off-by: Alessio Balsini <balsini@google.com>
Change-Id: I658c5ab2ebfe2b76d20685a099ac1b1fee3549cc