Revert "Revert "ITS#8240 remove obsolete assert""

We have never documented our use of assert, so can't expect
builders to do the right thing.
This reverts commit 55dd4d3275.

libraries/liblber/io.c

@@ -679,7 +679,7 @@ done:
 		return (ber->ber_tag);
 	}
 
-	assert( 0 ); /* ber structure is messed up ?*/
+	/* invalid input */
 	return LBER_DEFAULT;
 }