r.category manual: fs -> separator

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@55710 15284696-431f-4ddb-bdfa-cd5b030d7da7

raster/r.category/r.category.html

@@ -24,7 +24,7 @@ separate these fields in the output, by default.
 <p>
 The output is sent to standard output in the form of one category per line,
 with the category value first on the line, then an ASCII TAB character (or
-whatever single character or space is specified using the <b>fs</b>
+whatever single character or space is specified using the <b>separator</b>
 parameter), then the label for the category.