Only pass nomblk_io_submit option when mounting ext4

This option only exists for ext4 filesystems, so it shouldn't be
used when mounting ext2/ext3.
This bug would cause the mount system call in check_fs to always fail
with ext2/ext3 filesystems.

Change-Id: I3c8938029357a4a4170355118b6757f61ff4b227
1 file changed