perf script python: Add Python3 support to syscall-counts.py

Support both Python2 and Python3 in the syscall-counts.py script

There may be differences in the ordering of output lines due to
differences in dictionary ordering etc.  However the format within lines
should be unchanged.

The use of 'from __future__' implies the minimum supported Python2 version
is now v2.6
Signed-off-by: Tony Jones <tonyj@suse.de>
Link: http://lkml.kernel.org/r/20190222230619.17887-14-tonyj@suse.deSigned-off-by: Seeteena Thoufeek <s1seetee@linux.vnet.ibm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/scripts/python/syscall-counts.py

@@ -5,6 +5,8 @@
 # Displays system-wide system call totals, broken down by syscall.
 # If a [comm] arg is specified, only syscalls called by [comm] are displayed.
 
+from __future__ import print_function
+
 import os
 import sys
 
@@ -28,7 +30,7 @@ if len(sys.argv) > 1:
 syscalls = autodict()
 
 def trace_begin():
-	print "Press control+C to stop and show the summary"
+	print("Press control+C to stop and show the summary")
 
 def trace_end():
 	print_syscall_totals()
@@ -51,14 +53,14 @@ def syscalls__sys_enter(event_name, context, common_cpu,
 
 def print_syscall_totals():
     if for_comm is not None:
-	    print "\nsyscall events for %s:\n\n" % (for_comm),
+	    print("\nsyscall events for %s:\n" % (for_comm))
     else:
-	    print "\nsyscall events:\n\n",
+	    print("\nsyscall events:\n")
 
-    print "%-40s  %10s\n" % ("event", "count"),
-    print "%-40s  %10s\n" % ("----------------------------------------", \
-                                 "-----------"),
+    print("%-40s  %10s" % ("event", "count"))
+    print("%-40s  %10s" % ("----------------------------------------",
+                              "-----------"))
 
-    for id, val in sorted(syscalls.iteritems(), key = lambda(k, v): (v, k), \
+    for id, val in sorted(syscalls.items(), key = lambda kv: (kv[1], kv[0]), \
 				  reverse = True):
-	    print "%-40s  %10d\n" % (syscall_name(id), val),
+	    print("%-40s  %10d" % (syscall_name(id), val))