Fix mips64 build. Replace explicit cast with static_cast

Change-Id: Ib08fbe8bb832884a3eb33904fe4d490759116cb2
diff --git a/linker/linker_mips.cpp b/linker/linker_mips.cpp
index eb2ae84..7fbde3d 100644
--- a/linker/linker_mips.cpp
+++ b/linker/linker_mips.cpp
@@ -70,8 +70,8 @@
         if (ELF64_R_TYPE2(rel->r_info) != R_MIPS_64 ||
             ELF64_R_TYPE3(rel->r_info) != R_MIPS_NONE) {
           DL_ERR("Unexpected compound relocation type:%d type2:%d type3:%d @ %p (%zu)",
-                 type, (unsigned)ELF64_R_TYPE2(rel->r_info),
-                 (unsigned)ELF64_R_TYPE3(rel->r_info), rel, idx);
+                 type, static_cast<unsigned>(ELF64_R_TYPE2(rel->r_info)),
+                 static_cast<unsigned>(ELF64_R_TYPE3(rel->r_info)), rel, idx);
           return false;
         }
 #endif