Would you like to add more error handling for return values from functions like the following? * [fclose](https://pubs.opengroup.org/onlinepubs/9799919799/functions/fclose.html "Close a stream.") ⇒ [show_tags](https://github.com/error27/smatch/blob/2fb2b9093c5d001c7fd3ea58fe533df880dd2c44/ctags.c#L101) * [malloc](https://pubs.opengroup.org/onlinepubs/9799919799/functions/malloc.html "Memory allocation") ⇒ [register_state_assigned](https://github.com/error27/smatch/blob/2fb2b9093c5d001c7fd3ea58fe533df880dd2c44/smatch_state_assigned.c#L102) * [printf](https://pubs.opengroup.org/onlinepubs/9799919799/functions/fprintf.html "Print formatted output.") ⇒ [graph_ep](https://github.com/error27/smatch/blob/2fb2b9093c5d001c7fd3ea58fe533df880dd2c44/graph.c#L54-L63)
