binder: fix google-runtime-int

Bug: 162909698
Test: m libbinder

Change-Id: I63ec0e57166a97711d254156bde04ffe155465a5
diff --git a/libs/binder/Debug.cpp b/libs/binder/Debug.cpp
index 64c1ff6..da342ff 100644
--- a/libs/binder/Debug.cpp
+++ b/libs/binder/Debug.cpp
@@ -208,7 +208,7 @@
     }
 
     for (offset = 0; ; offset += bytesPerLine, pos += bytesPerLine) {
-        long remain = length;
+        size_t remain = length;
 
         char* c = buffer;
         if (!oneLine && !cStyle) {