auth.c comment nit : "an the" => "a"

[Jim Freeman]

--- src/usr.bin/ssh/auth.c	2013/02/05 22:29:53	1.1
+++ src/usr.bin/ssh/auth.c	2013/02/05 22:30:19
@@ -331,7 +331,7 @@
  *
  * XXX Should any specific check be done for sym links ?
  *
- * Takes an the file name, its stat information (preferably from fstat() to
+ * Takes a file name, its stat information (preferably from fstat() to
  * avoid races), the uid of the expected owner, their home directory and an
  * error buffer plus max size as arguments.
  *