Need to set the buffer size to allocate correctly

This may be a missing function call that was in the openssl version and
was removed here.
diff --git a/src/mbedtls.c b/src/mbedtls.c
index 428ecb0..d7c43f1 100644
--- a/src/mbedtls.c
+++ b/src/mbedtls.c
@@ -116,6 +116,7 @@
 	
 	TSize /= 8; // Comes in in bits not bytes.
 
+        cbOut = pcose->cbContent; // M00BUG - This is a missing call?
 	rgbOut = (byte *)COSE_CALLOC(cbOut+TSize, 1, context);
 	CHECK_CONDITION(rgbOut != NULL, COSE_ERR_OUT_OF_MEMORY);