build: fix compile issue in unittest on EPEL-5

When building the current master branch on EPEL-5, the following error
is observed:

      CC     dht_layout_unittest-dht_layout_mock.o
    unittest/dht_layout_mock.c:77:2: error: no newline at end of file
    make[5]: *** [dht_layout_unittest-dht_layout_mock.o] Error 1
    make[5]: *** Waiting for unfinished jobs....

EPEL-5 has this gcc:

    $ gcc --version
    gcc (GCC) 4.1.2 20080704 (Red Hat 4.1.2-54)

The fix is simple enough, dht_layout_unittest-dht_layout_mock.c should
have a line ending.

BUG: 1124858
Change-Id: I8ca7a1699fd1c35694073b9577f94ae525854713
Signed-off-by: Niels de Vos <ndevos@redhat.com>
Reviewed-on: http://review.gluster.org/8392
Reviewed-by: Lalatendu Mohanty <lmohanty@redhat.com>
Reviewed-by: Humble Devassy Chirammal <humble.devassy@gmail.com>
Reviewed-by: Kaleb KEITHLEY <kkeithle@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Luis Pabon <lpabon@redhat.com>