qed: Remove callback from qed_read_l2_table()

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
diff --git a/block/qed.h b/block/qed.h
index ce8c314..c715058 100644
--- a/block/qed.h
+++ b/block/qed.h
@@ -237,8 +237,7 @@
                             unsigned int n);
 int qed_read_l2_table_sync(BDRVQEDState *s, QEDRequest *request,
                            uint64_t offset);
-void qed_read_l2_table(BDRVQEDState *s, QEDRequest *request, uint64_t offset,
-                       BlockCompletionFunc *cb, void *opaque);
+int qed_read_l2_table(BDRVQEDState *s, QEDRequest *request, uint64_t offset);
 void qed_write_l2_table(BDRVQEDState *s, QEDRequest *request,
                         unsigned int index, unsigned int n, bool flush,
                         BlockCompletionFunc *cb, void *opaque);