[BOLT][NFC] Check errors from Obj.dynamicEntries

Addresses fuzzer crash

Reviewed By: rafauler

Differential Revision: https://reviews.llvm.org/D121336

Author: aaupov

bolt/lib/Rewrite/RewriteInstance.cpp

@@ -5135,8 +5135,10 @@ Error RewriteInstance::readELFDynamic(ELFObjectFile<ELFT> *File) {
                              "dynamic section sizes should match");
 
   // Go through all dynamic entries to locate entries of interest.
-  typename ELFT::DynRange DynamicEntries =
-      cantFail(Obj.dynamicEntries(), "error accessing dynamic table");
+  auto DynamicEntriesOrErr = Obj.dynamicEntries();
+  if (!DynamicEntriesOrErr)
+    return DynamicEntriesOrErr.takeError();
+  typename ELFT::DynRange DynamicEntries = DynamicEntriesOrErr.get();
 
   for (const Elf_Dyn &Dyn : DynamicEntries) {
     switch (Dyn.d_tag) {