Always use signed leb128 decoder

  Relocation packer no longer encodes relocation tables
  using unsigned leb128: https://android-review.googlesource.com/147745

Bug: http://b/18051137
Change-Id: I620b7188e5f3dd9d5123431aa1fc7feca76be607
diff --git a/linker/linker_mips.cpp b/linker/linker_mips.cpp
index c162111..0769f82 100644
--- a/linker/linker_mips.cpp
+++ b/linker/linker_mips.cpp
@@ -30,7 +30,7 @@
 #include "linker_debug.h"
 #include "linker_relocs.h"
 #include "linker_reloc_iterators.h"
-#include "linker_leb128.h"
+#include "linker_sleb128.h"
 
 template bool soinfo::relocate<plain_reloc_iterator>(plain_reloc_iterator&& rel_iterator,
                                                      const soinfo_list_t& global_group,
@@ -41,11 +41,6 @@
     const soinfo_list_t& global_group,
     const soinfo_list_t& local_group);
 
-template bool soinfo::relocate<packed_reloc_iterator<leb128_decoder>>(
-    packed_reloc_iterator<leb128_decoder>&& rel_iterator,
-    const soinfo_list_t& global_group,
-    const soinfo_list_t& local_group);
-
 template <typename ElfRelIteratorT>
 bool soinfo::relocate(ElfRelIteratorT&& rel_iterator,
                       const soinfo_list_t& global_group,