Fix minor bug in ps2port.c - can't check for -1 with unsigned return type.
diff --git a/src/ps2port.c b/src/ps2port.c
index 4cd8316..043d581 100644
--- a/src/ps2port.c
+++ b/src/ps2port.c
@@ -229,7 +229,7 @@
 
     // Receive parameters (if any).
     for (i = 0; i < receive; i++) {
-        u8 data = ps2_recvbyte(aux, 0, 200);
+        int data = ps2_recvbyte(aux, 0, 200);
         if (data < 0) {
             // On a receive timeout, return the item number that the
             // transfer failed on.