pcmcia: Use resource_size function on resource object

Cocinnele reports a warning

WARNING: Suspicious code. resource_size is maybe missing with root

The root cause is the function resource_size is not used when needed

Use resource_size() on variable "root" of type resource
Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>

drivers/pcmcia/yenta_socket.c

@@ -638,11 +638,11 @@ static int yenta_search_one_res(struct resource *root, struct resource *res,
 		start = PCIBIOS_MIN_CARDBUS_IO;
 		end = ~0U;
 	} else {
-		unsigned long avail = root->end - root->start;
+		unsigned long avail = resource_size(root);
 		int i;
 		size = BRIDGE_MEM_MAX;
-		if (size > avail/8) {
-			size = (avail+1)/8;
+		if (size > (avail - 1) / 8) {
+			size = avail / 8;
 			/* round size down to next power of 2 */
 			i = 0;
 			while ((size /= 2) != 0)