Apply suggestions from code review

Co-authored-by: benkrikler <mr.krikler@googlemail.com>

fast_plotter/postproc/functions.py

@@ -51,13 +51,13 @@ def handle_one_df(df, query=None, replacements=[],
     return df
 
 
-def query(df, query, engine_query=None):
+def query(df, query, engine=None):
     """
     Keep only rows that satisfy requirements of the query string,
     See: https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.query.html
     """
     logger.info("Applying query: %s", query)
-    return handle_one_df(df, query=query, engine_query=engine_query)
+    return handle_one_df(df, query=query, engine_query=engine)
 
 
 def rebin(df, axis, mapping, ignore_when_combining=None, rename=None, drop_others=False):