Improve handling of ContructBDFID errors

Building on this package on Fedora reports this warning
In file included from rpmbuild/BUILD/rocm_smi_lib-rocm-5.5.1/src/rocm_smi_main.cc:62:
In member function 'amd::smi::Device::set_bdfid(unsigned long)',
    inlined from 'amd::smi::RocmSMI::Initialize(unsigned long)' at rpmbuild/BUILD/rocm_smi_lib-rocm-5.5.1/src/rocm_smi_main.cc:330:27:
rpmbuild/BUILD/rocm_smi_lib-rocm-5.5.1/include/rocm_smi/rocm_smi_device.h:199:42: warning: 'bdfid' may be used uninitialized [-Wmaybe-uninitialized]
  199 |     void set_bdfid(uint64_t val) {bdfid_ = val;}
      |                                   ~~~~~~~^~~~~
rpmbuild/BUILD/rocm_smi_lib-rocm-5.5.1/src/rocm_smi_main.cc: In member function 'amd::smi::RocmSMI::Initialize(unsigned long)':
rpmbuild/BUILD/rocm_smi_lib-rocm-5.5.1/src/rocm_smi_main.cc:324:12: note: 'bdfid' was declared here
  324 |   uint64_t bdfid;
      |            ^~~~~

Only set the bdfid when it is know to be valid.

Signed-off-by: Tom Rix <trix@redhat.com>
Change-Id: I839b4d2d2d4e3b25469cf5972245b9630da00c87


[ROCm/amdsmi commit: 19c3e2aff9]

projects/amdsmi/src/rocm_smi_main.cc

@@ -345,8 +345,9 @@ RocmSMI::Initialize(uint64_t flags) {
     if (ConstructBDFID(devices_[i]->path(), &bdfid) != 0) {
       std::cerr << "Failed to construct BDFID." << std::endl;
       ret = 1;
+    } else {
+      devices_[i]->set_bdfid(bdfid);
     }
-    devices_[i]->set_bdfid(bdfid);
   }
   if (ret != 0) {
     throw amd::smi::rsmi_exception(RSMI_INITIALIZATION_ERROR,