fs: fs_parser: fix printk format warning

Fix printk format warning (seen on i386 builds) by using ptrdiff format
specifier (%t):

  fs/fs_parser.c:413:6: warning: format `%lu' expects argument of type `long unsigned int', but argument 3 has type `int' [-Wformat=]

Link: http://lkml.kernel.org/r/19432668-ffd3-fbb2-af4f-1c8e48f6cc81@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/fs_parser.c

@@ -410,7 +410,7 @@ bool fs_validate_description(const struct fs_parameter_description *desc)
 			for (param = desc->specs; param->name; param++) {
 				if (param->opt == e->opt &&
 				    param->type != fs_param_is_enum) {
-					pr_err("VALIDATE %s: e[%lu] enum val for %s\n",
+					pr_err("VALIDATE %s: e[%tu] enum val for %s\n",
 					       name, e - desc->enums, param->name);
 					good = false;
 				}