tools/kvm_stat: fix misc glitches

Addresses
- eliminate extra import
- missing variable initialization
- type redefinition from int to float
- passing of int type argument instead of string
- a couple of PEP8-reported indentation/formatting glitches
- remove unused variable drilldown in class Tui

Signed-off-by: Stefan Raspl <raspl@linux.vnet.ibm.com>
Reviewed-by: Marc Hartmayer <mhartmay@linux.vnet.ibm.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>

tools/kvm/kvm_stat/kvm_stat

@@ -31,7 +31,6 @@ import resource
 import struct
 import re
 from collections import defaultdict
-from time import sleep
 
 VMX_EXIT_REASONS = {
     'EXCEPTION_NMI':        0,
@@ -657,6 +656,7 @@ class DebugfsProvider(object):
         self._fields = self.get_available_fields()
         self._pid = 0
         self.do_read = True
+        self.paths = []
 
     def get_available_fields(self):
         """"Returns a list of available fields.
@@ -794,7 +794,6 @@ class Tui(object):
     def __init__(self, stats):
         self.stats = stats
         self.screen = None
-        self.drilldown = False
         self.update_drilldown()
 
     def __enter__(self):
@@ -950,11 +949,10 @@ class Tui(object):
         while True:
             self.refresh(sleeptime)
             curses.halfdelay(int(sleeptime * 10))
-            sleeptime = 3
+            sleeptime = 3.0
             try:
                 char = self.screen.getkey()
                 if char == 'x':
-                    self.drilldown = not self.drilldown
                     self.update_drilldown()
                 if char == 'q':
                     break
@@ -1066,7 +1064,7 @@ Requirements:
     optparser.add_option('-p', '--pid',
                          action='store',
                          default=0,
-                        type=int,
+                         type='int',
                          dest='pid',
                          help='restrict statistics to pid',
                          )
@@ -1099,8 +1097,8 @@ def check_access(options):
                          "Also ensure, that the kvm modules are loaded.\n")
         sys.exit(1)
 
-    if not os.path.exists(PATH_DEBUGFS_TRACING) and (options.tracepoints
-                                                     or not options.debugfs):
+    if not os.path.exists(PATH_DEBUGFS_TRACING) and (options.tracepoints or
+                                                     not options.debugfs):
         sys.stderr.write("Please enable CONFIG_TRACING in your kernel "
                          "when using the option -t (default).\n"
                          "If it is enabled, make {0} readable by the "
@@ -1111,7 +1109,7 @@ def check_access(options):
 
         sys.stderr.write("Falling back to debugfs statistics!\n")
         options.debugfs = True
-        sleep(5)
+        time.sleep(5)
 
     return options