Get rid of warnings when compiled with -Wformat-security

Change-Id: I63c3bf786bbe7a0276624e71a4ba80c4a9aaa4bb
diff --git a/rsProgram.cpp b/rsProgram.cpp
index 478a6dc..70e2868 100644
--- a/rsProgram.cpp
+++ b/rsProgram.cpp
@@ -195,7 +195,7 @@
 
     if (rsc->props.mLogShaders) {
         LOGV("Loading shader type %x, ID %i", type, mShaderID);
-        LOGV(mShader.string());
+        LOGV("%s", mShader.string());
     }
 
     if (mShaderID) {