[lld-macho] Fix unwind info personality size

This was missed by {D107035}. This fix addresses the following warning:

  loop variable 'personality' has type 'const uint32_t &' (aka 'const unsigned int &') but is initialized with type 'const unsigned long long' resulting in a copy [-Wrange-loop-analysis]

In addition to fixing the size, I also removed the const reference,
since there's no performance benefit to avoiding copies of integer-sized
values.

lld/MachO/UnwindInfoSection.cpp

@@ -572,7 +572,7 @@ void UnwindInfoSectionImpl<Ptr>::writeTo(uint8_t *buf) const {
     *i32p++ = encoding.first;
 
   // Personalities
-  for (const uint32_t &personality : personalities)
+  for (Ptr personality : personalities)
     *i32p++ =
         in.got->addr + (personality - 1) * target->wordSize - in.header->addr;