fpga/abcbus.sv: correct abc_xinpstb_s -> abc_xoutpstb_s

Incorrectly used abc_xinpstb_s instead of abc_xoutpstb_s in the
equation for xoutpstb_s.

fpga/abcbus.sv

@@ -106,8 +106,8 @@ module abcbus (
    reg	     abc80;
    wire      abc800 = ~abc80;
 
-   wire	     xinpstb_s  = (abc800 & abc_xinpstb_s) | (|abc_inp_s);
-   wire	     xoutpstb_s = (abc800 & abc_xinpstb_s) | (|abc_out_s);
+   wire	     xinpstb_s  = (abc800 & abc_xinpstb_s)  | (|abc_inp_s);
+   wire	     xoutpstb_s = (abc800 & abc_xoutpstb_s) | (|abc_out_s);
    // Memory and I/O read/write strobes for ABC-bus
    reg	     abc_xmemrd;
    reg       abc_xmemwr;