virSecurityDACRestoreSecurityHostdevLabel: Unmark @def as unused

The domain definition is clearly used a few lines
below so there's no need to mark @def as unused.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

src/security/security_dac.c

@@ -598,7 +598,7 @@ virSecurityDACRestoreSecuritySCSILabel(virSCSIDevicePtr dev ATTRIBUTE_UNUSED,
 
 static int
 virSecurityDACRestoreSecurityHostdevLabel(virSecurityManagerPtr mgr,
-                                          virDomainDefPtr def ATTRIBUTE_UNUSED,
+                                          virDomainDefPtr def,
                                           virDomainHostdevDefPtr dev,
                                           const char *vroot)