Tweak location-based detection logic

Signed-off-by: Jesse Vincent <jesse@keyboard.io>

bin/find-device-port-macos

@@ -69,10 +69,13 @@ sub try_for_raw_serialnum {
 sub try_for_location_id {
     my $location_id = shift;
 
-    # Here, also, the final character is always a "1", so if macOS ever stops doing that, this
-    # will need an update, as well.
-    my $loc = substr($location_id, 2, 3);
-    exit_with_port_if_exists("/dev/cu.usbmodem" . $loc . 1);
+    # macOS truncates the string of "0"s from the right of the location id.
+    # Here, also, the final character is an appended "1", so if macOS ever stops doing that,
+    # this will need an update, as well. 
+    if ($location_id =~ /0x(\d+?)0*\b/) {
+        my $loc = $1;
+        exit_with_port_if_exists("/dev/cu.usbmodem" . $loc . "1");
+    }
 }
 
 sub try_for_sn_prefix {