selinux: drop the BUG() in cred_has_capability()

With the compile time check located immediately above the
cred_has_capability() function ensuring that we will notice if the
capability set grows beyond 63 capabilities, we can safely remove
the BUG() call from the cred_has_capability().

Signed-off-by: Paul Moore <paul@paul-moore.com>

security/selinux/hooks.c

@@ -1659,7 +1659,6 @@ static int cred_has_capability(const struct cred *cred,
 		break;
 	default:
 		pr_err("SELinux:  out of range capability %d\n", cap);
-		BUG();
 		return -EINVAL;
 	}