meminfo: Fix dmabufinfo total ref accounting

The number of references to a buffer total_refs was not accounting for
a process holding multiple references to the same buffer.

Also, clarify AppendDmaBufInfo functionality in comments

Change-Id: I044a18acad1570492a925d51b9464d5b0e60ca35
Signed-off-by: Erick Reyes <erickreyes@google.com>
diff --git a/libmeminfo/libdmabufinfo/dmabufinfo.cpp b/libmeminfo/libdmabufinfo/dmabufinfo.cpp
index b4ad667..0212cd2 100644
--- a/libmeminfo/libdmabufinfo/dmabufinfo.cpp
+++ b/libmeminfo/libdmabufinfo/dmabufinfo.cpp
@@ -130,7 +130,7 @@
             if (buf->count() == 0)
                 buf->SetCount(count);
             buf->AddFdRef(pid);
-            return true;
+            continue;
         }
 
         DmaBuffer& db =