diffcore-rename.c: use ALLOC_GROW()

Use ALLOC_GROW() instead of open-coding it in locate_rename_dst()
and register_rename_src().

Signed-off-by: Dmitry S. Dolzhenko <dmitrys.dolzhenko@yandex.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diffcore-rename.c

@@ -38,11 +38,7 @@ static struct diff_rename_dst *locate_rename_dst(struct diff_filespec *two,
 	if (!insert_ok)
 		return NULL;
 	/* insert to make it at "first" */
-	if (rename_dst_alloc <= rename_dst_nr) {
-		rename_dst_alloc = alloc_nr(rename_dst_alloc);
-		rename_dst = xrealloc(rename_dst,
-				      rename_dst_alloc * sizeof(*rename_dst));
-	}
+	ALLOC_GROW(rename_dst, rename_dst_nr + 1, rename_dst_alloc);
 	rename_dst_nr++;
 	if (first < rename_dst_nr)
 		memmove(rename_dst + first + 1, rename_dst + first,
@@ -82,11 +78,7 @@ static struct diff_rename_src *register_rename_src(struct diff_filepair *p)
 	}
 
 	/* insert to make it at "first" */
-	if (rename_src_alloc <= rename_src_nr) {
-		rename_src_alloc = alloc_nr(rename_src_alloc);
-		rename_src = xrealloc(rename_src,
-				      rename_src_alloc * sizeof(*rename_src));
-	}
+	ALLOC_GROW(rename_src, rename_src_nr + 1, rename_src_alloc);
 	rename_src_nr++;
 	if (first < rename_src_nr)
 		memmove(rename_src + first + 1, rename_src + first,