get rid of pointless includes of ext2_fs.h

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

init/do_mounts_initrd.c

@@ -2,7 +2,6 @@
 #include <linux/kernel.h>
 #include <linux/fs.h>
 #include <linux/minix_fs.h>
-#include <linux/ext2_fs.h>
 #include <linux/romfs_fs.h>
 #include <linux/initrd.h>
 #include <linux/sched.h>