libertas: fix CF firmware loading for some cards

if_cs_poll_while_fw_download() returned the number of iterations
remaining on success, which in turn got returned as the value from
if_cs_prog_real() and if_cs_prog_helper().  But since if_cs_probe()
interprets non-zero return values from firmware load functions as an
error, this sometimes caused spurious firmware load failures.
Signed-off-by: NDan Williams <dcbw@redhat.com>
Tested-by: NRyan Mallon <ryan@bluewatersys.com>
Acked-by: NRyan Mallon <ryan@bluewatersys.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

drivers/net/wireless/libertas/if_cs.c

@@ -151,7 +151,7 @@ static int if_cs_poll_while_fw_download(struct if_cs_card *card, uint addr, u8 r
 	for (i = 0; i < 100000; i++) {
 		u8 val = if_cs_read8(card, addr);
 		if (val == reg)
-			return i;
+			return 0;
 		udelay(5);
 	}
 	return -ETIME;