Include fcntl.h, not sys/fcntl.h so we get the definition

of the open system call.  That is what man page says to do.
Fixes warning on Solaris.

This commit was SVN r24073.

orte/mca/debugger/mpirx/mpirx.c

@@ -26,7 +26,7 @@
 #endif
 #include <sys/stat.h>
 #include <ctype.h>
-#include <sys/fcntl.h>
+#include <fcntl.h>
 #include <errno.h>
 
 #include "opal/util/argv.h"