apply: don't print on stdout in verbosity_silent mode

When apply_verbosity is set to verbosity_silent nothing should be printed on both stderr and stdout. To avoid printing on stdout, we can just skip calling the following functions: - stat_patch_list(), - numstat_patch_list(), - summary_patch_list(). It is safe to do that because the above functions have no side effects other than printing: - stat_patch_list() only computes some local values and then call show_stats() and print_stat_summary(), those two functions only compute local values and call printing functions, - numstat_patch_list() also only computes local values and calls printing functions, - summary_patch_list() calls show_file_mode_name(), printf(), show_rename_copy(), show_mode_change() that are only printing. Signed-off-by: Christian Couder <chriscool@tuxfamily.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>