Add a missing header (for sscanf).

opal/mca/common/verbs_usnic/common_verbs_usnic_fake.c

@@ -42,6 +42,7 @@
 #include <sys/types.h>
 #include <dirent.h>
 #include <string.h>
+#include <stdio.h>
 #include <infiniband/verbs.h>
 #ifdef HAVE_INFINIBAND_DRIVER_H
 #include <infiniband/driver.h>