msm: xo: Add NULL pointer and error pointer check

Add NULL pointer check since msm_get_xo() might return NULL due to
RPM is not available. Also add error pointer check to make msm_xo_*
APIs more defensive.

Change-Id: Ie20ae974215e05430a3d5d8cc826774cbe243f51
Signed-off-by: Tianyi Gou <tgou@codeaurora.org>
1 file changed