patch 9.0.0828: various typos

Problem:    Various typos.
Solution:   Correct typos. (closes #11432)
diff --git a/src/spellfile.c b/src/spellfile.c
index 3c934fc..b5db526 100644
--- a/src/spellfile.c
+++ b/src/spellfile.c
@@ -4588,7 +4588,7 @@
      *    (si_compress_cnt == 1) and the number of free nodes drops below the
      *    maximum word length.
      */
-#ifndef SPELL_COMPRESS_ALLWAYS
+#ifndef SPELL_COMPRESS_ALWAYS
     if (spin->si_compress_cnt == 1
 	    ? spin->si_free_count < MAXWLEN
 	    : spin->si_blocks_cnt >= compress_start)