Handle percentile lists with higher precision that 2 digits

We cap the output at %2.2f right now, that's not always enough.
Make the parser check and store the precision required to
output the list correctly.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/options.c b/options.c
index 4522fe4..42a2ea0 100644
--- a/options.c
+++ b/options.c
@@ -2434,6 +2434,7 @@
 		.name	= "percentile_list",
 		.type	= FIO_OPT_FLOAT_LIST,
 		.off1	= td_var_offset(percentile_list),
+		.off2	= td_var_offset(percentile_precision),
 		.help	= "Specify a custom list of percentiles to report",
 		.def    = "1:5:10:20:30:40:50:60:70:80:90:95:99:99.5:99.9:99.95:99.99",
 		.maxlen	= FIO_IO_U_LIST_MAX_LEN,