eicon: fix sparse integer as NULL pointer warnings

drivers/isdn/hardware/eicon/message.c:745:47: warning: Using plain integer as NULL pointer
drivers/isdn/hardware/eicon/message.c:761:45: warning: Using plain integer as NULL pointer
drivers/isdn/hardware/eicon/message.c:9122:16: warning: Using plain integer as NULL pointer
drivers/isdn/hardware/eicon/message.c:9147:16: warning: Using plain integer as NULL pointer
drivers/isdn/hardware/eicon/message.c:9173:14: warning: Using plain integer as NULL pointer
drivers/isdn/hardware/eicon/divasmain.c:396:23: warning: Using plain integer as NULL pointer

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Cc: Karsten Keil <kkeil@suse.de>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/isdn/hardware/eicon/divasmain.c b/drivers/isdn/hardware/eicon/divasmain.c
index 6d39f93..5fcbdcc 100644
--- a/drivers/isdn/hardware/eicon/divasmain.c
+++ b/drivers/isdn/hardware/eicon/divasmain.c
@@ -393,7 +393,7 @@
 	dma_addr_t dma_handle;
 	void *addr_handle;
 
-	for (i = 0; (pmap != 0); i++) {
+	for (i = 0; (pmap != NULL); i++) {
 		diva_get_dma_map_entry(pmap, i, &cpu_addr, &phys_addr);
 		if (!cpu_addr) {
 			break;