[PATCH] PnP bugfix

I forgot the errno.h.  Without this patch, things may not compile when
pnp support or pnp card support is disabled.

Hope you had a good trip.  I noticed a small mistake in pnp 0.93 and I have
a fix for it.

include/linux/pnp.h

@@ -11,6 +11,7 @@
 
 #include <linux/device.h>
 #include <linux/list.h>
+#include <linux/errno.h>
 
 
 /*