Revert "[Mellanox] Redirect ethtool stderr to subprocess for better error log (#12038)" (#12183)

This reverts commit 9750cb4.

There is a PR to handle 202205 branch revert: #12184

- Why I did it
The PR to be reverted introduced many notice logs every 1 minute if SFP is not plugged:

Cannot get module EEPROM information: Input/output error
Before the "bad" PR, the message format is like this:

INFO pmon#supervisord: xcvrd Cannot get module EEPROM information: Input/output error
It was truncated by rsyslog because every message is the same. However, the "bad" PR introduces SFP index to the message:

NOTICE pmon#xcvrd: Failed to get EEPROM data for sfp 39: Cannot get module EEPROM information: Input/output error
Rsyslog no longer truncate such log and many such messages are flooded to syslog.

- How I did it
Revert the PR

- How to verify it
Manual test

platform/mellanox/mlnx-platform-api/sonic_platform/sfp.py

@@ -359,8 +359,7 @@ class SFP(NvidiaSFPCommon):
         try:
             output = subprocess.check_output(ethtool_cmd,
                                              shell=True,
-                                             universal_newlines=True,
-                                             stderr=subprocess.PIPE)
+                                             universal_newlines=True)
             output_lines = output.splitlines()
             first_line_raw = output_lines[0]
             if "Offset" in first_line_raw:
@@ -368,7 +367,6 @@ class SFP(NvidiaSFPCommon):
                     line_split = line.split()
                     eeprom_raw = eeprom_raw + line_split[1:]
         except subprocess.CalledProcessError as e:
-            logger.log_notice("Failed to get EEPROM data for sfp {}: {}".format(self.index, e.stderr))
             return None
 
         eeprom_raw = list(map(lambda h: int(h, base=16), eeprom_raw))