[hwasan] Fix tests when vm.overcommit_memory=1.

[eugenis]

Summary

Remove an invalid check from sizes.cpp that only passes when overcommit is disabled.

Fixes PR48274.

[pcc]

LGTM

compiler-rt/test/hwasan/TestCases/sizes.cpp

int main(int argc, char **argv) {
   static const size_t kChunkHeaderSize = 16;
 
   size_t MallocSize = test_size_max ? std::numeric_limits<size_t>::max()
                                     : (kMaxAllowedMallocSize + 1);
 
   if (!untag_strcmp(argv[1], "malloc")) {
     void *p = malloc(MallocSize);
     assert(!p);
-    p = malloc(kMaxAllowedMallocSize - kChunkHeaderSize);
-    assert(!p);
   } else if (!untag_strcmp(argv[1], "calloc")) {
     // Trigger an overflow in calloc.
     size_t size = std::numeric_limits<size_t>::max();
     void *p = calloc((size / 0x1000) + 1, 0x1000);
     assert(!p);
   } else if (!untag_strcmp(argv[1], "reallocarray")) {
     // Trigger an overflow in reallocarray.
     size_t size = std::numeric_limits<size_t>::max();