input: synaptics_dsx_2.6: correct suspend path for Synaptics V2.6 driver

Correct the suspend path for Synaptics V2.6 driver by adding the brackets
in the error path while calling the pinctrl call. This change will make
the driver not go into undesirable path and complete the function calls
necessary for suspend routine.

Change-Id: I327eff97f584cefb2c957c43e9820f3a37d4751c
Signed-off-by: Shantanu Jain <shjain@codeaurora.org>