mount: Add LOG_PREFIX

It's very convenient to grep the log for mount related operations only.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

mount.c

@@ -32,6 +32,9 @@
 
 #define AUTODETECTED_MOUNT "CRIU:AUTOGENERATED"
 
+#undef	LOG_PREFIX
+#define LOG_PREFIX "mnt: "
+
 int ext_mount_add(char *key, char *val)
 {
 	struct ext_mount *em;