Fix query for CPU count.

Some devices report fewer processors online versus
configured.  Always get the configured (higher) number

bug 18108290

Change-Id: Ic6202e05ad8c4686dd79795f880baf5429674d70
diff --git a/cpu_ref/rsCpuCore.cpp b/cpu_ref/rsCpuCore.cpp
index 31cf6f8..47bc1c0 100644
--- a/cpu_ref/rsCpuCore.cpp
+++ b/cpu_ref/rsCpuCore.cpp
@@ -265,7 +265,7 @@
 
     GetCpuInfo();
 
-    int cpu = sysconf(_SC_NPROCESSORS_ONLN);
+    int cpu = sysconf(_SC_NPROCESSORS_CONF);
     if(mRSC->props.mDebugMaxThreads) {
         cpu = mRSC->props.mDebugMaxThreads;
     }