smcinvoke: Fix the error of repeated definition of size_add

Conflicts with this commit from upstream: 2b46db3

drivers/soc/qcom/smcinvoke.c

@@ -898,7 +898,7 @@ static struct smcinvoke_cb_txn *find_cbtxn_locked(
  * size_add saturates at SIZE_MAX. If integer overflow is detected,
  * this function would return SIZE_MAX otherwise normal a+b is returned.
  */
-static inline size_t size_add(size_t a, size_t b)
+static inline size_t _size_add(size_t a, size_t b)
 {
 	return (b > (SIZE_MAX - a)) ? SIZE_MAX : a + b;
 }
@@ -918,7 +918,7 @@ static inline size_t pad_size(size_t a, size_t b)
  */
 static inline size_t size_align(size_t a, size_t b)
 {
-	return size_add(a, pad_size(a, b));
+	return _size_add(a, pad_size(a, b));
 }
 
 static uint16_t get_server_id(int cb_server_fd)
@@ -1767,7 +1767,7 @@ static size_t compute_in_msg_size(const struct smcinvoke_cmd_req *req,
 
 	/* each buffer has to be 8 bytes aligned */
 	while (i < SMCI_OBJECT_COUNTS_NUM_BUFFERS(req->counts))
-		total_size = size_add(total_size,
+		total_size = _size_add(total_size,
 				size_align(args_buf[i++].b.size,
 				SMCINVOKE_ARGS_ALIGN_SIZE));