rescue+extra: move fio into base+bench

It's 15 Mb off x86_64 regular-rescue.iso as of today
(libicu and a few other hefty libraries are only needed
for fio), and benchmarks are probably a better company
albeit fio could be useful as a stress testing tool.

pkg.in/lists/tagged/base+bench

@@ -13,6 +13,7 @@ stream-mem
 bonnie
 bonnie++
 iozone
+fio
 ffsb
 
 # networking

pkg.in/lists/tagged/rescue+extra

@@ -18,7 +18,8 @@ disktype
 #     would suddenly get busy otherwise
 #evms
 #evms-ncurses
-fio
+# fio pulls in a bunch of huge libraries down to libicu
+#fio
 gpart
 hddtemp
 idle3-tools