msm: kgsl: Remove kzalloc failure message

Remove kzalloc failure message from kgsl_iommu_clk_disable_on_ts.
A lot of other stuff would go bad if kzalloc fails so we don't
really need this message.

Change-Id: Ifcd8b93b23b4669423e276dda765703d5c06248d
Signed-off-by: Shrenuj Bansal <shrenujb@codeaurora.org>