msm: ipa3: Fix to NULL pointer dereference

Accessing the ipa3_ctx structure pointer before
initializing it. Added code changes to fix NULL
pointer dereference issue.

Change-Id: Ic81cf3bf2f3368d92cf393fba37af6f54a5bce8c
Acked-by: Ashok Vuyyuru <avuyyuru@qti.qualcomm.com>
Signed-off-by: Mohammed Javid <mjavid@codeaurora.org>