test: [refactor] Simplify submit_block_catch_error

Make it catch any Exception and let the caller verify it.

This refactor does not change any behavior, but the code is simpler,
more flexible and still correct, because wait_for_node_exit enforces the
crash to happen.

test/functional/feature_dbcrash.py

@@ -25,10 +25,7 @@
          - restart until recovery succeeds
          - check that utxo matches node3 using gettxoutsetinfo"""
 
-import errno
-import http.client
 import random
-import subprocess
 import time
 
 from test_framework.blocktools import COINBASE_MATURITY
@@ -90,7 +87,7 @@ class ChainstateWriteCrashTest(BitcoinTestFramework):
             except Exception:
                 # An exception here should mean the node is about to crash.
                 # If bitcoind exits, then try again.  wait_for_node_exit()
-                # should raise an exception if bitcoind doesn't exit.
+                # enforces that bitcoind crashed.
                 self.wait_for_node_exit(node_index, timeout=10)
             self.crashed_on_restart += 1
 
@@ -105,25 +102,15 @@ class ChainstateWriteCrashTest(BitcoinTestFramework):
         """Try submitting a block to the given node.
 
         Catch any exceptions that indicate the node has crashed.
+        The caller will check that a crash happened.
         Returns true if the block was submitted successfully; false otherwise."""
 
         try:
             self.nodes[node_index].submitblock(block)
             return True
-        except (http.client.CannotSendRequest, http.client.RemoteDisconnected) as e:
+        except Exception as e:
             self.log.debug(f"node {node_index} submitblock raised exception: {e}")
             return False
-        except subprocess.CalledProcessError as e:
-            self.log.debug(f"node {node_index} submitblock raised CalledProcessError: {e}")
-            return False
-        except OSError as e:
-            self.log.debug(f"node {node_index} submitblock raised OSError exception: errno={e.errno}")
-            if e.errno in [errno.EPIPE, errno.ECONNREFUSED, errno.ECONNRESET]:
-                # The node has likely crashed
-                return False
-            else:
-                # Unexpected exception, raise
-                raise
 
     def sync_node3blocks(self, block_hashes):
         """Use submitblock to sync node3's chain with the other nodes
@@ -149,6 +136,7 @@ class ChainstateWriteCrashTest(BitcoinTestFramework):
                 if not self.submit_block_catch_error(i, block):
                     # TODO: more carefully check that the crash is due to -dbcrashratio
                     # (change the exit code perhaps, and check that here?)
+                    # wait_for_node_exit() enforces that bitcoind crashed.
                     self.wait_for_node_exit(i, timeout=30)
                     self.log.debug(f"Restarting node {i} after block hash {block_hash}")
                     nodei_utxo_hash = self.restart_node(i, block_hash)