config.c: rearrange xcalloc arguments

xcalloc() takes two arguments: the number of elements and their size.
config.c includes several calls to xcalloc() that pass the arguments
in reverse order: the size of a struct lock_file*, followed by the
number to allocate.

Rearrange them so they are in the correct order.

Signed-off-by: Brian Gesiak <modocache@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

config.c

@@ -1538,7 +1538,7 @@ int git_config_set_multivar_in_file(const char *config_filename,
 	 * The lock serves a purpose in addition to locking: the new
 	 * contents of .git/config will be written into it.
 	 */
-	lock = xcalloc(sizeof(struct lock_file), 1);
+	lock = xcalloc(1, sizeof(struct lock_file));
 	fd = hold_lock_file_for_update(lock, config_filename, 0);
 	if (fd < 0) {
 		error("could not lock config file %s: %s", config_filename, strerror(errno));
@@ -1793,7 +1793,7 @@ int git_config_rename_section_in_file(const char *config_filename,
 	if (!config_filename)
 		config_filename = filename_buf = git_pathdup("config");
 
-	lock = xcalloc(sizeof(struct lock_file), 1);
+	lock = xcalloc(1, sizeof(struct lock_file));
 	out_fd = hold_lock_file_for_update(lock, config_filename, 0);
 	if (out_fd < 0) {
 		ret = error("could not lock config file %s", config_filename);