test: refactor: remove unnecessary blocks_checked counter

Since we already store all the blocks in `events`, keeping an
additional counter is redundant.

Author: stickies-v

test/functional/interface_usdt_validation.py

@@ -86,7 +86,6 @@ def __repr__(self):
                     self.duration)
 
         BLOCKS_EXPECTED = 2
-        blocks_checked = 0
         expected_blocks = dict()
         events = []
 
@@ -98,11 +97,10 @@ def __repr__(self):
                   usdt_contexts=[ctx], debug=0)
 
         def handle_blockconnected(_, data, __):
-            nonlocal events, blocks_checked
+            nonlocal events
             event = ctypes.cast(data, ctypes.POINTER(Block)).contents
             self.log.info(f"handle_blockconnected(): {event}")
             events.append(event)
-            blocks_checked += 1
 
         bpf["block_connected"].open_perf_buffer(
             handle_blockconnected)
@@ -127,7 +125,7 @@ def handle_blockconnected(_, data, __):
             # only plausibility checks
             assert event.duration > 0
             del expected_blocks[block_hash]
-        assert_equal(BLOCKS_EXPECTED, blocks_checked)
+        assert_equal(BLOCKS_EXPECTED, len(events))
         assert_equal(0, len(expected_blocks))
 
         bpf.cleanup()