Remove bogus std::error_code returns form SectionRef.

There are two methods in SectionRef that can fail:

* getName: The index into the string table can be invalid.
* getContents: The section might point to invalid contents.

Every other method will always succeed and returning and std::error_code just
complicates the code. For example, a section can have an invalid alignment,
but if we are able to get to the section structure at all and create a
SectionRef, we will always be able to read that invalid alignment.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219314 91177308-0d34-0410-b5e6-96231b3b80d8

lib/ProfileData/CoverageMappingReader.cpp

@@ -333,7 +333,8 @@ struct SectionData {
   std::error_code load(SectionRef &Section) {
     if (auto Err = Section.getContents(Data))
       return Err;
-    return Section.getAddress(Address);
+    Address = Section.getAddress();
+    return instrprof_error::success;
   }
 
   std::error_code get(uint64_t Pointer, size_t Size, StringRef &Result) {