Use String8/16 c_str [graphics]

Bug: 295394788
Test: make checkbuild
Change-Id: I605c6c25c2415bdb4996715f270ee8be9e9d1a23
Merged-In: I605c6c25c2415bdb4996715f270ee8be9e9d1a23
diff --git a/libs/hwui/renderthread/RenderThread.cpp b/libs/hwui/renderthread/RenderThread.cpp
index 01b956c..7952e70 100644
--- a/libs/hwui/renderthread/RenderThread.cpp
+++ b/libs/hwui/renderthread/RenderThread.cpp
@@ -345,7 +345,7 @@
 
     String8 cachesOutput;
     mCacheManager->dumpMemoryUsage(cachesOutput, mRenderState);
-    dprintf(fd, "\nPipeline=%s\n%s\n", pipelineToString(), cachesOutput.string());
+    dprintf(fd, "\nPipeline=%s\n%s\n", pipelineToString(), cachesOutput.c_str());
 }
 
 void RenderThread::getMemoryUsage(size_t* cpuUsage, size_t* gpuUsage) {