Minor linker cleanup, primarily to use Elf32_Dyn

Change-Id: Ifa9408e9859c6f79444715bed4808b7c13fdced5
diff --git a/linker/linker_phdr.cpp b/linker/linker_phdr.cpp
index 94260fa..acd18cd 100644
--- a/linker/linker_phdr.cpp
+++ b/linker/linker_phdr.cpp
@@ -550,7 +550,7 @@
 phdr_table_get_dynamic_section(const Elf32_Phdr* phdr_table,
                                int               phdr_count,
                                Elf32_Addr        load_bias,
-                               Elf32_Addr**      dynamic,
+                               Elf32_Dyn**       dynamic,
                                size_t*           dynamic_count,
                                Elf32_Word*       dynamic_flags)
 {
@@ -562,7 +562,7 @@
             continue;
         }
 
-        *dynamic = (Elf32_Addr*)(load_bias + phdr->p_vaddr);
+        *dynamic = reinterpret_cast<Elf32_Dyn*>(load_bias + phdr->p_vaddr);
         if (dynamic_count) {
             *dynamic_count = (unsigned)(phdr->p_memsz / 8);
         }