trace-cmd: Add calc_page_offset() helper routine
trace-cmd: Add calc_page_offset() helper routine

Use calc_page_offset() to performe the:

	offset & (handle->page_size - 1)

to prevent any typos and bugs.

Signed-off-by: Steven Rostedt <43232e92d70cc7aa53504ad0397085ee47bad87f@goodmis.org>

bigzz/trace-cmd,bigzz/trace-cmd