patch 9.1.0581: Various lines are indented inconsistently

Problem:  style: Various lines are indented inconsistently
Solution: Retab these lines and correct some comments.
          (zeertzjq)

closes: #15259

Signed-off-by: zeertzjq <zeertzjq@outlook.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/gui.c b/src/gui.c
index 25662ef..8e7b079 100644
--- a/src/gui.c
+++ b/src/gui.c
@@ -460,7 +460,7 @@
     // and in that case we don't want to overwrite ligatures map that has already
     // been correctly populated (as that would lead to a cleared ligatures maps).
     if (*p_guiligatures == NUL)
-        CLEAR_FIELD(gui.ligatures_map);
+	CLEAR_FIELD(gui.ligatures_map);
 #endif
 
 #if defined(ALWAYS_USE_GUI) || defined(VIMDLL)