blkin: fix cmake compile options

Signed-off-by: Sage Weil <sage@redhat.com>

diff --git a/src/blkin b/src/blkin
index c54b5c5586de3469b6ee1c107a7e4f32f7e51724..5abc87260bf2e95cac453ecd8d892682d445a0e1 160000 (submodule)
--- a/src/blkin
+++ b/src/blkin
@@ -1 +1 @@
-Subproject commit c54b5c5586de3469b6ee1c107a7e4f32f7e51724
+Subproject commit 5abc87260bf2e95cac453ecd8d892682d445a0e1