tree-wide: apply equals-null.cocci

Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/builtin/replace.c b/builtin/replace.c
index 946938d..402d9e3 100644
--- a/builtin/replace.c
+++ b/builtin/replace.c
@@ -72,7 +72,7 @@ static int list_replace_refs(const char *pattern, const char *format)
 {
 	struct show_data data;
 
-	if (pattern == NULL)
+	if (!pattern)
 		pattern = "*";
 	data.pattern = pattern;