ext3: Get rid of extenddisksize parameter of ext3_get_blocks_handle()

Get rid of extenddisksize parameter of ext3_get_blocks_handle(). This seems to
be a relict from some old days and setting disksize in this function does not
make much sence. Currently it was set only by ext3_getblk().  Since the
parameter has some effect only if create == 1, it is easy to check that the
three callers which end up calling ext3_getblk() with create == 1 (ext3_append,
ext3_quota_write, ext3_mkdir) do the right thing and set disksize themselves.

Signed-off-by: Jan Kara <jack@suse.cz>