COMPMID-417: Fix memory manager in NEDirectConvolution.

Moves the accumulator manage call to the cases that is actually used.

Change-Id: I80486913142860b394aad9d4b486166a2dfaf269
Reviewed-on: http://mpd-gerrit.cambridge.arm.com/88620
Tested-by: Kaizen <jeremy.johnson+kaizengerrit@arm.com>
Reviewed-by: Moritz Pflanzer <moritz.pflanzer@arm.com>
1 file changed