osmux: Do not divide the number of bytes by eight.

sizeof(uint8_t) == 1 and there is no need to create an array
with 16 bytes and then only use the first two of them. This
means the CID range is from 0 to 127 and we should be able
to extend this to 256 by changing the array size to 32. Update
the testcase now that we can have more than 16 calls with Osmux.
diff --git a/openbsc/src/libmgcp/mgcp_osmux.c b/openbsc/src/libmgcp/mgcp_osmux.c
index b0ef69f..30a81cb 100644
--- a/openbsc/src/libmgcp/mgcp_osmux.c
+++ b/openbsc/src/libmgcp/mgcp_osmux.c
@@ -536,7 +536,7 @@
 {
 	int i, j, used = 0;
 
-	for (i = 0; i < sizeof(osmux_cid_bitmap) / 8; i++) {
+	for (i = 0; i < sizeof(osmux_cid_bitmap); i++) {
 		for (j = 0; j < 8; j++) {
 			if (osmux_cid_bitmap[i] & (1 << j))
 				used += 1;
@@ -550,7 +550,7 @@
 {
 	int i, j;
 
-	for (i = 0; i < sizeof(osmux_cid_bitmap) / 8; i++) {
+	for (i = 0; i < sizeof(osmux_cid_bitmap); i++) {
 		for (j = 0; j < 8; j++) {
 			if (osmux_cid_bitmap[i] & (1 << j))
 				continue;