Fix race condition in t9119-git-svn-info.sh

Fix race condition in t9119-git-svn-info.sh

Changed the ptouch bash function to use the "Text Last Updated"
date reported by 'svn info' when changing the modified time
(mtime) of the file/symlink/directory in the git working
directory.  Previously it used the mtime of the item in the
svn working directory, which caused the race condition.

[ew: swapped argument order of ptouch() to minimize diff]

From: David D. Kilzer <ddkilzer@kilzer.net>

Signed-off-by: David D. Kilzer <ddkilzer@kilzer.net>
Acked-by: Eric Wong <normalperson@yhbt.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>