Fix typo: sqml -> sgml.

diff --git a/Makefile.in b/Makefile.in
index 8972329..3bf57fd 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -13,7 +13,7 @@
 # etags:           create a TAGS file for Emacs.
 # manpages:        compile manpages for Wine API
 # htmlpages:       compile html pages for Wine API
-# sgmlpages:       compile sqml source for the Wine API Guide
+# sgmlpages:       compile sgml source for the Wine API Guide
 
 # Directories