Merge pull request #8790 from pquerna/objc_fix_leak_of_buffer

Objective-C: Fix memory leak of every message sent
diff --git a/src/objective-c/GRPCClient/private/GRPCWrappedCall.m b/src/objective-c/GRPCClient/private/GRPCWrappedCall.m
index 627b6aa..38fcae0 100644
--- a/src/objective-c/GRPCClient/private/GRPCWrappedCall.m
+++ b/src/objective-c/GRPCClient/private/GRPCWrappedCall.m
@@ -112,7 +112,7 @@
 }
 
 - (void)dealloc {
-  gpr_free(_op.data.send_message);
+  grpc_byte_buffer_destroy(_op.data.send_message);
 }
 
 @end