Attest: Rename useful_buf to q_useful_buf

Set proper namespace to indicate that q_usful_buf
is originated from QCBOR library and to prevent
namespace collison.

Change-Id: I00a10ccc052dd4d4757f1c451d6534385e58ef00
Signed-off-by: Laurence Lundblade <lgl@securitytheory.com>
Co-authored-by: Tamas Ban <tamas.ban@arm.com>
diff --git a/lib/t_cose/src/t_cose_util.h b/lib/t_cose/src/t_cose_util.h
index 7b39dc3..5539862 100644
--- a/lib/t_cose/src/t_cose_util.h
+++ b/lib/t_cose/src/t_cose_util.h
@@ -13,9 +13,13 @@
 #define __T_COSE_UTIL_H__
 
 #include <stdint.h>
-#include "useful_buf.h"
+#include "q_useful_buf.h"
 #include "t_cose_common.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /**
  * \file t_cose_util.h
  *
@@ -79,10 +83,10 @@
  * "TBS" bytes.
  */
 enum t_cose_err_t create_tbs_hash(int32_t cose_alg_id,
-                                  struct useful_buf buffer_for_hash,
-                                  struct useful_buf_c *hash,
-                                  struct useful_buf_c protected_headers,
-                                  struct useful_buf_c payload);
+                                  struct q_useful_buf buffer_for_hash,
+                                  struct q_useful_buf_c *hash,
+                                  struct q_useful_buf_c protected_headers,
+                                  struct q_useful_buf_c payload);
 
 
 /**
@@ -120,7 +124,11 @@
  *
  */
 enum t_cose_err_t
-get_short_circuit_kid(struct useful_buf buffer_for_kid,
-                      struct useful_buf_c *kid);
+get_short_circuit_kid(struct q_useful_buf buffer_for_kid,
+                      struct q_useful_buf_c *kid);
+
+#ifdef __cplusplus
+}
+#endif
 
 #endif /* __T_COSE_UTIL_H__ */