ps_matched: xcalloc() takes nmemb and then element size

Even though multiplication is commutative, the order of arguments
should be xcalloc(nmemb, size).  ps_matched is an array of 1-byte
element whose size is the same as the number of pathspec elements.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/checkout.c

@@ -280,7 +280,7 @@ static int checkout_paths(const struct checkout_opts *opts,
 	if (opts->source_tree)
 		read_tree_some(opts->source_tree, &opts->pathspec);
 
-	ps_matched = xcalloc(1, opts->pathspec.nr);
+	ps_matched = xcalloc(opts->pathspec.nr, 1);
 
 	/*
 	 * Make sure all pathspecs participated in locating the paths

builtin/ls-files.c

@@ -516,7 +516,7 @@ int cmd_ls_files(int argc, const char **argv, const char *cmd_prefix)
 
 	/* Treat unmatching pathspec elements as errors */
 	if (pathspec.nr && error_unmatch)
-		ps_matched = xcalloc(1, pathspec.nr);
+		ps_matched = xcalloc(pathspec.nr, 1);
 
 	if ((dir.flags & DIR_SHOW_IGNORED) && !exc_given)
 		die("ls-files --ignored needs some exclude pattern");