homing: Remove EndstopError

There's no reason to distinguish between an EndstopError and a
CommandError, so just use CommandError.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

klippy/homing.py

@@ -101,8 +101,8 @@ class Homing:
             for s, name, spos, epos in end_mcu_pos:
                 if spos == epos:
                     if probe_pos:
-                        raise EndstopError("Probe triggered prior to movement")
-                    raise EndstopError(
+                        raise CommandError("Probe triggered prior to movement")
+                    raise CommandError(
                         "Endstop %s still triggered after retract" % (name,))
     def home_rails(self, rails, forcepos, movepos):
         # Notify of upcoming homing operation
@@ -161,7 +161,4 @@ def multi_complete(printer, completions):
 class CommandError(Exception):
     pass
 
-class EndstopError(CommandError):
-    pass
-
 Coord = collections.namedtuple('Coord', ('x', 'y', 'z', 'e'))