nbd: do not include block_int.h

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/nbd.c b/nbd.c
index 4c6d7f1..d4dafc6 100644
--- a/nbd.c
+++ b/nbd.c
@@ -18,7 +18,6 @@
 
 #include "nbd.h"
 #include "block.h"
-#include "block_int.h"
 
 #include "qemu-coroutine.h"
 
@@ -703,7 +702,7 @@
     exp->bs = bs;
     exp->dev_offset = dev_offset;
     exp->nbdflags = nbdflags;
-    exp->size = size == -1 ? exp->bs->total_sectors * 512 : size;
+    exp->size = size == -1 ? bdrv_getlength(bs) : size;
     return exp;
 }