Fix Android build of elf_mem_image.cc (#1052)

diff --git a/absl/debugging/internal/elf_mem_image.cc b/absl/debugging/internal/elf_mem_image.cc
index d6832ea..29a2818 100644
--- a/absl/debugging/internal/elf_mem_image.cc
+++ b/absl/debugging/internal/elf_mem_image.cc
@@ -222,7 +222,7 @@
       reinterpret_cast<ElfW(Dyn) *>(dynamic_program_header->p_vaddr +
                                     relocation);
   for (; dynamic_entry->d_tag != DT_NULL; ++dynamic_entry) {
-    const ElfW(Xword) value = dynamic_entry->d_un.d_val + relocation;
+    const auto value = dynamic_entry->d_un.d_val + relocation;
     switch (dynamic_entry->d_tag) {
       case DT_HASH:
         hash_ = reinterpret_cast<ElfW(Word) *>(value);