disp: msm: dsi: fix return value for alter_esd_check_mode

The file operation write expects a non zero return value for a
successful exit from the file op.

Change-Id: I5e956333f39c33708ba24e2722713484c613f0ee
Signed-off-by: Satya Rama Aditya Pinapala <psraditya30@codeaurora.org>