io_uring: remove any grabbing of context

The async workers are siblings of the task itself, so by definition we
have all the state that we need. Remove any of the state grabbing that
we have, and requests flagging what they need.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs/io-wq.h

@@ -11,13 +11,6 @@ enum {
 	IO_WQ_WORK_UNBOUND	= 4,
 	IO_WQ_WORK_CONCURRENT	= 16,
 
-	IO_WQ_WORK_FILES	= 32,
-	IO_WQ_WORK_FS		= 64,
-	IO_WQ_WORK_MM		= 128,
-	IO_WQ_WORK_CREDS	= 256,
-	IO_WQ_WORK_BLKCG	= 512,
-	IO_WQ_WORK_FSIZE	= 1024,
-
 	IO_WQ_HASH_SHIFT	= 24,	/* upper 8 bits are used for hash key */
 };