powerpc: Make open count variables signed in hvcs/hvsi/hvc_console

Otherwise the tests for count < 0 will never be true.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/drivers/char/hvc_console.h b/drivers/char/hvc_console.h
index 8297dbc..3c85d78 100644
--- a/drivers/char/hvc_console.h
+++ b/drivers/char/hvc_console.h
@@ -48,7 +48,7 @@
 	spinlock_t lock;
 	int index;
 	struct tty_struct *tty;
-	unsigned int count;
+	int count;
 	int do_wakeup;
 	char *outbuf;
 	int outbuf_size;