staging: lustre: ptlrpc: fix magic return value of ptlrpc_init_portals

Previously, when running 'modprobe lustre', it hit the following
error message which is becaue of network initialisation failure:
modprobe: ERROR: could not insert 'lustre': Input/output error

However, error code is there, just let it return to caller,
after this patch, error message will be something like:
modprobe: ERROR: could not insert 'lustre': Network is down
Signed-off-by: Wang Shilong <wshilong@ddn.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-5455
Reviewed-on: http://review.whamcloud.com/11337Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: James Simmons <uja.ornl@gmail.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/lustre/lustre/ptlrpc/events.c

@@ -543,7 +543,7 @@ static int ptlrpc_ni_init(void)
 	rc = LNetNIInit(pid);
 	if (rc < 0) {
 		CDEBUG(D_NET, "Can't init network interface: %d\n", rc);
-		return -ENOENT;
+		return rc;
 	}
 
 	/* CAVEAT EMPTOR: how we process portals events is _radically_
@@ -561,7 +561,7 @@ static int ptlrpc_ni_init(void)
 	CERROR("Failed to allocate event queue: %d\n", rc);
 	LNetNIFini();
 
-	return -ENOMEM;
+	return rc;
 }
 
 int ptlrpc_init_portals(void)
@@ -570,7 +570,7 @@ int ptlrpc_init_portals(void)
 
 	if (rc != 0) {
 		CERROR("network initialisation failed\n");
-		return -EIO;
+		return rc;
 	}
 	rc = ptlrpcd_addref();
 	if (rc == 0)