Fix infinite loop

'ret' could be set to non-zero inside the loop and the 'cmac->bufferSz' never gets reset causing 'add' to become 0 in the subsequent loop.

wolfcrypt/src/cmac.c

@@ -211,7 +211,7 @@ int wc_CmacUpdate(Cmac* cmac, const byte* in, word32 inSz)
     /* Clear CRYPTOCB_UNAVAILABLE return code */
     ret = 0;
 
-    while (inSz != 0) {
+    while ((ret == 0) && (inSz != 0)) {
         word32 add = min(inSz, AES_BLOCK_SIZE - cmac->bufferSz);
         XMEMCPY(&cmac->buffer[cmac->bufferSz], in, add);