s/mxio_get_startup_handle/mx_get_startup_handle/

For MG-228: "get startup handles should not live in mxio"

Change-Id: I41dd9813091363b015c446aac0641d62441883c3
diff --git a/benchmarks/spec_fixture.cc b/benchmarks/spec_fixture.cc
index 1abed9c..8c83edf 100644
--- a/benchmarks/spec_fixture.cc
+++ b/benchmarks/spec_fixture.cc
@@ -21,8 +21,8 @@
 #include <launchpad/launchpad.h>
 #include <launchpad/vmo.h>
 #include <magenta/syscalls.h>
+#include <magenta/process.h>
 #include <magenta/processargs.h>
-#include <mxio/util.h>
 #include <magenta/syscalls/object.h>
 #endif
 
@@ -161,7 +161,7 @@
                           mx_handle_t* process) {
   launchpad_t* lp = NULL;
   mx_handle_t job_to_child = MX_HANDLE_INVALID;
-  mx_handle_t job = mxio_get_startup_handle(MX_HND_INFO(MX_HND_TYPE_JOB, 0));
+  mx_handle_t job = mx_get_startup_handle(MX_HND_INFO(MX_HND_TYPE_JOB, 0));
   if (job != MX_HANDLE_INVALID) {
     mx_handle_duplicate(job, MX_RIGHT_SAME_RIGHTS, &job_to_child);
   }