perf tools: Fix column width setting on 'trace' sort key

perf tools: Fix column width setting on 'trace' sort key

It missed to update column length of the 'trace' sort key in the
hists__calc_col_len() so it might truncate the output.  It calculated
the column length in the ->cmp() callback originally but it doesn't
guarantee it's called always.

Signed-off-by: Namhyung Kim <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>