Update bmusb.

diff --git a/bmusb b/bmusb
index 5549bd2f3d5a20e125b0b2b2096b017348a74834..6790c4a2d84ebf265dd0a3cbfe4e99e0ba3314b7 160000 (submodule)
--- a/bmusb
+++ b/bmusb
@@ -1 +1 @@
-Subproject commit 5549bd2f3d5a20e125b0b2b2096b017348a74834
+Subproject commit 6790c4a2d84ebf265dd0a3cbfe4e99e0ba3314b7