RDMA/core: Remove ucontext->closing

Nothing reads this any more, and the reason for its existence has passed
due to the deferred fput() scheme.

Fixes: 8ea1f98 ("drivers/IB,usnic: reduce scope of mmap_sem")
Link: https://lore.kernel.org/r/0-v1-df64ff042436+42-uctx_closing_jgg@nvidia.com
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/core/rdma_core.c

@@ -889,7 +889,6 @@ void uverbs_destroy_ufile_hw(struct ib_uverbs_file *ufile,
 	if (!ufile->ucontext)
 		goto done;
 
-	ufile->ucontext->closing = true;
 	ufile->ucontext->cleanup_retryable = true;
 	while (!list_empty(&ufile->uobjects))
 		if (__uverbs_cleanup_ufile(ufile, reason)) {

include/rdma/ib_verbs.h

@@ -1477,12 +1477,6 @@ struct ib_rdmacg_object {
 struct ib_ucontext {
 	struct ib_device       *device;
 	struct ib_uverbs_file  *ufile;
-	/*
-	 * 'closing' can be read by the driver only during a destroy callback,
-	 * it is set when we are closing the file descriptor and indicates
-	 * that mm_sem may be locked.
-	 */
-	bool closing;
 
 	bool cleanup_retryable;