SWDEV-357246 - Fixes to return with a error code instead of segfault in alloc failure case

Change-Id: Ie18d50f2f7ef3f4b2c0153152fca057232c1f8a2

hipamd/src/hip_hmm.cpp

@@ -226,6 +226,9 @@ hipError_t ihipMallocManaged(void** ptr, size_t size, unsigned int align) {
   }
   size_t offset = 0; //this is ignored
   amd::Memory* memObj = getMemoryObject(*ptr, offset);
+  if (memObj == nullptr) {
+    return hipErrorMemoryAllocation;
+  }
   //saves the current device id so that it can be accessed later
   memObj->getUserData().deviceId = hip::getCurrentDevice()->deviceId();