block: remove keep_read_only flag from BlockDriverState struct

The keep_read_only flag is no longer used, in favor of the bdrv
flag BDRV_O_ALLOW_RDWR.
Signed-off-by: NJeff Cody <jcody@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

block.c

@@ -812,8 +812,6 @@ int bdrv_open(BlockDriverState *bs, const char *filename, int flags,
         flags |= BDRV_O_ALLOW_RDWR;
     }
 
-    bs->keep_read_only = !(flags & BDRV_O_ALLOW_RDWR);
-
     /* Open the image */
     ret = bdrv_open_common(bs, filename, flags, drv);
     if (ret < 0) {

block_int.h

@@ -275,7 +275,6 @@ struct BlockDriverState {
     int64_t total_sectors; /* if we are reading a disk image, give its
                               size in sectors */
     int read_only; /* if true, the media is read only */
-    int keep_read_only; /* if true, the media was requested to stay read only */
     int open_flags; /* flags used to open the file, re-used for re-open */
     int encrypted; /* if true, the media is encrypted */
     int valid_key; /* if true, a valid encryption key has been set */