toolhead: Avoid pausing an infinitesimal amount of time

Only pause if the duration is worthwhile.  Due to differences in mcu
clock vs system clock it's possible to repeatedly underestimate a
system delay needed to bring about a sufficient mcu time - which just
wastes cpu cycles retrying a pause.  Once the time difference is
negligible it's okay to continue.

Signed-off-by: Kevin O'Connor <[email protected]>

Author: KevinOConnor

klippy/toolhead.py

@@ -332,7 +332,7 @@ def _check_pause(self):
         # Check if there are lots of queued moves and pause if so
         while 1:
             pause_time = buffer_time - BUFFER_TIME_HIGH
-            if pause_time <= 0.:
+            if pause_time < .005:
                 break
             if not self.can_pause:
                 self.need_check_pause = self.reactor.NEVER