[ Network Graph ] Temporal Fix in getInputGrad

[ Network Graph ] Temporal Fix in getInputGrad

When we turn on the inPlaceOptimization, it will fail if we have
mulitiple inputs: input layer ( can be inplace operatation ), normal
layers. Then, we are not allocate the grad between input layer and
this layer and it cause the error during calcDeriviate which requires
the grad tensor of input layer.

This patch fix this temporally by creating tensor buffer it reqruies.

and it includes modification of mem_check script to generate proper
output.

**Self evaluation:**
1. Build test:	 [X]Passed [ ]Failed [ ]Skipped
2. Run test:	 [X]Passed [ ]Failed [ ]Skipped

Signed-off-by: jijoong.moon <jijoong.moon@samsung.com>