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/search.c b/src/search.c
index 0b39d90..d1eb500 100644
--- a/src/search.c
+++ b/src/search.c
@@ -5106,11 +5106,11 @@
     int		    j = 0;
 
     if (str == NULL || pat == NULL)
-        return NULL;
+	return NULL;
 
     match_positions = ALLOC_ONE(garray_T);
     if (match_positions == NULL)
-        return NULL;
+	return NULL;
     ga_init2(match_positions, sizeof(int_u), 10);
 
     if (!fuzzy_match(str, pat, FALSE, &score, matches, MAX_FUZZY_MATCHES)