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/popupmenu.c b/src/popupmenu.c
index c18c97f..c116b10 100644
--- a/src/popupmenu.c
+++ b/src/popupmenu.c
@@ -527,7 +527,7 @@
 	else
 #endif
 	    attr = attrs[col - col_start];
-        screen_puts_len(ptr, char_len, row, col, attr);
+	screen_puts_len(ptr, char_len, row, col, attr);
 	col += mb_ptr2cells(ptr);
 	ptr += char_len;
     }