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/hvsi.c b/drivers/char/hvsi.c
index 59c6f9a..af05528 100644
--- a/drivers/char/hvsi.c
+++ b/drivers/char/hvsi.c
@@ -75,7 +75,7 @@
 	spinlock_t lock;
 	int index;
 	struct tty_struct *tty;
-	unsigned int count;
+	int count;
 	uint8_t throttle_buf[128];
 	uint8_t outbuf[N_OUTBUF]; /* to implement write_room and chars_in_buffer */
 	/* inbuf is for packet reassembly. leave a little room for leftovers. */