Start making RS 64-bit clean.

Change-Id: Ie40ad9a1d2b59094c86eb7e40b358e60120ce213
diff --git a/driver/rsdBcc.cpp b/driver/rsdBcc.cpp
index 77e0576..709d181 100644
--- a/driver/rsdBcc.cpp
+++ b/driver/rsdBcc.cpp
@@ -70,7 +70,7 @@
                             const Allocation * ain,
                             Allocation * aout,
                             const void * usr,
-                            uint32_t usrLen,
+                            size_t usrLen,
                             const RsScriptCall *sc) {
 
     RsdCpuReference::CpuScript *cs = (RsdCpuReference::CpuScript *)s->mHal.drv;