msm: ipa3: Fix to correct mem allocated flag

We are setting memory allocated as false even before
freeing system memory. Due to which memory deallocation
is bypassed.Remove the improper resetting of mem allocated
flag.

Change-Id: Ib2204b2541fe131d23270becf4cfbb47463bdf98
Signed-off-by: Praveen Kurapati <pkurapat@codeaurora.org>