VFS: Export dquot_send_warning

Sending a message to userspace in a generic format to warn
of events (e.g. quota exceeded) in the quota subsystem is
a generically useful feature. This patch makes some minor
changes to the send_message function from dquot.c renaming
it quota_send_message, moving it to quota.c and exporting it
for use by filesystems which do not use the dquot code.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
diff --git a/include/linux/quota.h b/include/linux/quota.h
index 78c4889..ce9a9b2 100644
--- a/include/linux/quota.h
+++ b/include/linux/quota.h
@@ -376,6 +376,17 @@
 	return flags >> _DQUOT_STATE_FLAGS;
 }
 
+#ifdef CONFIG_QUOTA_NETLINK_INTERFACE
+extern void quota_send_warning(short type, unsigned int id, dev_t dev,
+			       const char warntype);
+#else
+static inline void quota_send_warning(short type, unsigned int id, dev_t dev,
+				      const char warntype)
+{
+	return;
+}
+#endif /* CONFIG_QUOTA_NETLINK_INTERFACE */
+
 struct quota_info {
 	unsigned int flags;			/* Flags for diskquotas on this device */
 	struct mutex dqio_mutex;		/* lock device while I/O in progress */