Include what you use: <fcntl.h>

This was transitively included, but no longer is, so it must be
explicitly included.

Exempt-From-Owner-Approval: Janitorial
Test: build
Change-Id: I87dcb78bcd4a9539ae442344c9ab90c1fb0376e9
diff --git a/cpu_ref/rsCpuExecutable.cpp b/cpu_ref/rsCpuExecutable.cpp
index 82e3738..cc7f7a5 100644
--- a/cpu_ref/rsCpuExecutable.cpp
+++ b/cpu_ref/rsCpuExecutable.cpp
@@ -1,6 +1,7 @@
 #include "rsCpuExecutable.h"
 #include "rsCppUtils.h"
 
+#include <fcntl.h>
 #include <fstream>
 #include <set>
 #include <memory>