wilc1000: fix a loop timeout condition

If the loop fails, the "while(trials--) {" loop will exit with "trials"
set to -1.  The test for that expects it to end with "trials" set to 0
so the warning message will not be printed.

Fix this by changing from a post-op to a pre-op.  This does mean that
we only make 99 attempts instead of 100 but that's okay.

Fixes: f135a157 ("wilc1000: Support chip sleep over SPI")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Ajay Singh <ajay.kathat@microchip.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/YFS5gx/gi70zlIaO@mwanda

drivers/net/wireless/microchip/wilc1000/wlan.c

@@ -575,7 +575,7 @@ void chip_allow_sleep(struct wilc *wilc)
 		to_host_from_fw_bit = WILC_SPI_FW_TO_HOST_BIT;
 	}
 
-	while (trials--) {
+	while (--trials) {
 		ret = hif_func->hif_read_reg(wilc, to_host_from_fw_reg, &reg);
 		if (ret)
 			return;