tests/redpanda: Don't exclude redpanda with ']' in args

A change was introduced in 81c37c5 that attempted to fix an issue where
an incorrect process was selected as the redpanda process.  The
unintended side-effect was that any actual Redpanda process that
contained a ']' was excluded so methods like `self.redpanda.stop()`
wouldn't actually stop Redpanda as it was unable to find the appropriate
PID.

Fixed `ps` line to exclude "[redpanda]" rather than just "]".

Signed-off-by: Michael Boquard <[email protected]>

tests/rptest/services/redpanda.py

@@ -2254,7 +2254,7 @@ def remove_local_data(self, node):
 
     def redpanda_pid(self, node):
         try:
-            cmd = "ps ax | grep -i 'redpanda' | grep -v grep | grep -v 'version'| grep -v \"]\" | awk '{print $1}'"
+            cmd = "ps ax | grep -i 'redpanda' | grep -v grep | grep -v 'version'| grep -v \"\[redpanda\]\" | awk '{print $1}'"
             for p in node.account.ssh_capture(cmd,
                                               allow_fail=True,
                                               callback=int):