memleak on torchLoadModel

[filipecosta90]

==28935== 48 bytes in 1 blocks are definitely lost in loss record 95,420 of 132,320
==28935==    at 0x4C3017F: operator new(unsigned long) (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==28935==    by 0x6A8A814: torchLoadModel (torch_c.cpp:323)
==28935==    by 0x6A7A0E5: RAI_ModelCreateTorch (torch.c:42)
==28935==    by 0x67E6B05: RAI_ModelCreate (model.c:209)
==28935==    by 0x67D784B: RedisAI_ModelSet_RedisCommand (redisai.c:620)
==28935==    by 0x1C76BE: RedisModuleCommandDispatcher (module.c:575)
==28935==    by 0x13D315: call (server.c:2468)
==28935==    by 0x13DFCA: processCommand (server.c:2763)
==28935==    by 0x14F086: processInputBuffer (networking.c:1470)
==28935==    by 0x14F1DB: processInputBufferAndReplicate (networking.c:1505)
==28935==    by 0x14F551: readQueryFromClient (networking.c:1587)
==28935==    by 0x1342E2: aeProcessEvents (ae.c:443)

[lantiga]

Here we return the memory allocated from within the libtorch_c library as an opaque pointer, and then deallocate it by calling into libtorch_c when the model is DEL'd. However we don't call MODELDEL in tests. At this point we probably should, what do you think @filipecosta90 .

[filipecosta90]

hi there @lantiga ,
I've added libtorch.so to the ignored for now analysis on valgrind.
Notwithstanding there is a leak on. corrected on #296

  ret->devicestr = RedisModule_Strdup(devicestr);

==13436== Thread 1:
==13436== 4 bytes in 1 blocks are definitely lost in loss record 18 of 11,520
==13436==    at 0x4C2FB0F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==13436==    by 0x144D38: zmalloc (zmalloc.c:99)
==13436==    by 0x144F83: zstrdup (zmalloc.c:210)
==13436==    by 0x1C7006: RM_Strdup (module.c:352)
==13436==    by 0x89ECA54: RAI_ModelCreateTorch (in /home/filipe/redislabs/RedisAI/bin/linux-x64-cpu/install/backends/redisai_torch/redisai_torch.so)
==13436==    by 0x67CA207: RedisAI_ModelSet_RedisCommand (in /home/filipe/redislabs/RedisAI/bin/linux-x64-cpu/install/redisai.so)
==13436==    by 0x1C76BE: RedisModuleCommandDispatcher (module.c:575)
==13436==    by 0x13D315: call (server.c:2468)
==13436==    by 0x13DFCA: processCommand (server.c:2763)
==13436==    by 0x14F086: processInputBuffer (networking.c:1470)
==13436==    by 0x14F1DB: processInputBufferAndReplicate (networking.c:1505)
==13436==    by 0x14F551: readQueryFromClient (networking.c:1587)