go/neo/t/neotest: Use python -c 'print ...' in a way that works on both py2 and py3

Without parenthesis it was failing on py3:

	(neo) (py3.venv) (g.env) kirr@deca:~/src/neo/src/lab.nexedi.com/kirr/neo/go/neo/t$ ./neotest info-local
	date:   Wed, 18 May 2022 11:05:50 +0300
	xnode:  kirr@deca.navytux.spb.ru (2401:5180:0:af::1 192.168.0.3 (+ 1·ipv4))
	uname:  Linux deca 5.10.0-13-amd64 #1 SMP Debian 5.10.106-1 (2022-03-17) x86_64 GNU/Linux
	cpu:    Intel(R) Core(TM) i7-7600U CPU @ 2.80GHz
	  File "<string>", line 1
	    print '%.2fGHz' % (400000 / 1E6)
	          ^
	SyntaxError: invalid syntax

go/neo/t/neotest

 #!/bin/bash -e
 # neotest: run tests and benchmarks against FileStorage, ZEO and various NEO/py and NEO/go clusters
 
-# Copyright (C) 2017-2020  Nexedi SA and Contributors.
+# Copyright (C) 2017-2022  Nexedi SA and Contributors.
 #                          Kirill Smelkov <kirr@nexedi.com>
 #
 # This program is free software: you can Use, Study, Modify and Redistribute
@@ -562,7 +562,7 @@ proginfo() {
 
 # fkghz file	- extract value from file (in KHz) and render it as GHz
 fkghz() {
-	python -c "print '%.2fGHz' % (`cat $1` / 1E6)"
+	python -c "print('%.2fGHz' % (`cat $1` / 1E6))"
 }
 
 # lspci1 <pcidev> <field>	- show <field> from lspci information about <pcidev>
@@ -855,7 +855,7 @@ system_info() {
 		s+=", txqlen=`cat $nic/tx_queue_len`"
 		if test -e $nic/gro_flush_timeout ; then
 			tgroflush_ns=`cat $nic/gro_flush_timeout`
-			s+=", gro_flush_timeout=`python -c "print '%.3f' % ($tgroflush_ns / 1E3)"`µs"
+			s+=", gro_flush_timeout=`python -c "print('%.3f' % ($tgroflush_ns / 1E3))"`µs"
 		else
 			s+=", !gro_flush_timeout"
 		fi
@@ -874,7 +874,7 @@ system_info() {
 	printf "%-20s" "sw/python:";	proginfo python --version 2>&1	# https://bugs.python.org/issue18338
 	printf "%-20s" "sw/go:";	proginfo go version
 	printf "%-20s" "sw/sqlite:";	proginfo python -c \
-		'import sqlite3 as s; print "sqlite %s (py mod %s)" % (s.sqlite_version, s.version)'
+		'import sqlite3 as s; print("sqlite %s (py mod %s)" % (s.sqlite_version, s.version))'
 	printf "%-20s" "sw/mysqld:";	proginfo mysqld --version
 
 	pyver neoppod neo
@@ -1019,7 +1019,7 @@ Benchmark$1-avg 1 \\3 \\4/op\
 # hostof <url>		- return hostname part of <url>
 hostof() {
 	url=$1
-	python -c "import urlparse as p; u=p.urlparse(\"scheme://$url\"); print u.hostname"
+	python -c "import urlparse as p; u=p.urlparse(\"scheme://$url\"); print(u.hostname)"
 }
 
 # bench_net <url>	- benchmark network