block-backend: Make blk_inc/dec_in_flight public

For some users of BlockBackends, just increasing the in_flight counter
is easier than implementing separate handlers in BlockDevOps. Make the
helper functions for this public.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

block/block-backend.c

@@ -1262,12 +1262,12 @@ int blk_make_zero(BlockBackend *blk, BdrvRequestFlags flags)
     return bdrv_make_zero(blk->root, flags);
 }
 
-static void blk_inc_in_flight(BlockBackend *blk)
+void blk_inc_in_flight(BlockBackend *blk)
 {
     atomic_inc(&blk->in_flight);
 }
 
-static void blk_dec_in_flight(BlockBackend *blk)
+void blk_dec_in_flight(BlockBackend *blk)
 {
     atomic_dec(&blk->in_flight);
     aio_wait_kick();

include/sysemu/block-backend.h

@@ -156,6 +156,8 @@ int blk_co_pdiscard(BlockBackend *blk, int64_t offset, int bytes);
 int blk_co_flush(BlockBackend *blk);
 int blk_flush(BlockBackend *blk);
 int blk_commit_all(void);
+void blk_inc_in_flight(BlockBackend *blk);
+void blk_dec_in_flight(BlockBackend *blk);
 void blk_drain(BlockBackend *blk);
 void blk_drain_all(void);
 void blk_set_on_error(BlockBackend *blk, BlockdevOnError on_read_error,