selinux: Remove unused function avc_sidcmp()

Remove the function avc_sidcmp() that is not used anywhere.

This was partially found by using a static code analysis program called cppcheck.
Signed-off-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
[PM: rewrite the patch subject line]
Signed-off-by: Paul Moore <pmoore@redhat.com>

security/selinux/avc.c

@@ -517,11 +517,6 @@ int __init avc_add_callback(int (*callback)(u32 event), u32 events)
 	return rc;
 }
 
-static inline int avc_sidcmp(u32 x, u32 y)
-{
-	return (x == y || x == SECSID_WILD || y == SECSID_WILD);
-}
-
 /**
  * avc_update_node Update an AVC entry
  * @event : Updating event