owfs: avoid npe in BUS_reset function

Monitor adapters (zeroconf, enet, usb and w1) don't have the reset
routine, causing null pointer dereference in BUS_reset function.

This patch has been submitted upstream:
https://sourceforge.net/p/owfs/bugs/67/

Signed-off-by: Marcin Jurkowski <marcin1j@gmail.com>

utils/owfs/patches/101-fix-no-reset-routine-segfault.patch

@@ -0,0 +1,13 @@
+--- a/module/owlib/src/c/ow_reset.c
++++ b/module/owlib/src/c/ow_reset.c
+@@ -21,6 +21,10 @@ RESET_TYPE BUS_reset(const struct parsed
+ 	struct connection_in * in = pn->selected_connection ;
+ 	STAT_ADD1_BUS(e_bus_resets, in);
+ 
++	if ( in->iroutines.reset == NO_RESET_ROUTINE ) {
++		return BUS_RESET_OK;
++	}
++
+ 	switch ( (in->iroutines.reset) (pn) ) {
+ 	case BUS_RESET_OK:
+ 		in->reconnect_state = reconnect_ok;	// Flag as good!