I have found a few articles that say he was rescued but also a picture of the unmarked grave of Percy Ball in Hollybrook cemetery, Lordswood, Lordshill, Southhampton.

The sites says it belongs to Titanic related graves and describes Percy Ball as indeed a steward.

This is the link;

http://www.titanic-titanic.com/southampton_titanic_graves.shtml

Last group of pictures, near bottom of page.

I am wondering if he was a titanic survivor but died later on.
There was also mention of a survivor named Percy Bell havind died at war but I have checked dates and they do not match, others confirmed this at the forums.

Hope this helps.