patch 9.1.0783: 'spell' option setting has problems

Problem:  'spell' option setting has problems
Solution: correctly check for comma for 'spellfile' option,
          remove unnecessary checks, refactor slightly (Milly)

closes: #15873

Signed-off-by: Milly <milly.ca@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/optionstr.c b/src/optionstr.c
index bf7135a..b1bb39a 100644
--- a/src/optionstr.c
+++ b/src/optionstr.c
@@ -3584,7 +3584,7 @@
 
     // If there is a window for this buffer in which 'spell' is set load the
     // wordlists.
-    return did_set_spell_option(TRUE);
+    return did_set_spell_option();
 }
 
 /*
@@ -3600,7 +3600,7 @@
 
     // If there is a window for this buffer in which 'spell' is set load the
     // wordlists.
-    return did_set_spell_option(FALSE);
+    return did_set_spell_option();
 }
 
 /*