Add missing header file that caused compilation errors in the

rhc-step2b branch last night.

This commit was SVN r17453.

ompi/mca/btl/openib/btl_openib_component.c

@@ -27,6 +27,7 @@
 #include <infiniband/verbs.h>
 #include <errno.h>
 #include <string.h>   /* for strerror()*/
+#include <unistd.h>
 
 #include "ompi/constants.h"
 #include "opal/event/event.h"