selftests: ublk: cleanup kublk.h

Arguments are handled via flags so
remove unused no_auto_part_scan bitfield.

Signed-off-by: Alexander Atanasov <alex@zazolabs.com>

Author: zazolabs

tools/testing/selftests/ublk/kublk.h

@@ -79,7 +79,6 @@ struct dev_ctx {
 	unsigned int	per_io_tasks:1;
 	unsigned int	no_ublk_fixed_fd:1;
 	unsigned int	safe_stop:1;
-	unsigned int	no_auto_part_scan:1;
 	__u32 integrity_flags;
 	__u8 metadata_size;
 	__u8 pi_offset;