perf hists browser: Fix first column printing

As a side effect of commit f5951d56a2ab ("perf hists browser: Use
perf_hpp__format functions") perf report TUI got a problem of not
refreshing the first character.

Since the previous patch restores the column width of "overhead" to 7
we can start at column 0 now.

Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1347431706-7839-2-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>