Clean up docstring

Author: calvingiles

src/google/adk/tools/mcp_tool/mcp_tool.py

@@ -74,7 +74,6 @@ def __init__(
         mcp_session_manager: The MCP session manager to use for communication.
         auth_scheme: The authentication scheme to use.
         auth_credential: The authentication credential to use.
-        errlog: TextIO stream for error logging.
         tool_name_prefix: string to add to the start of the tool name. For example,
           `prefix="ns_"` would name `my_tool` as `ns_my_tool`.