LU-723 fsfilt: Remove EXT4_EXT_HAS_NO_TREE macro

LU-723 fsfilt: Remove EXT4_EXT_HAS_NO_TREE macro

This change removes the EXT4_EXT_HAS_NO_TREE macro and any logic which
is based on the definition of this macro. From now on, this macro is
assumed to be defined.

Signed-off-by: Prakash Surya <surya1@llnl.gov>
Change-Id: I13af4c44d7cafef53fe45cf5e143053054d6ee50
Reviewed-on: http://review.whamcloud.com/3080
Tested-by: Hudson
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: James Simmons <uja.ornl@gmail.com>