Use consistent quoting in linker messages.

Using single quotes can be more convenient -- because there's no need to
escape -- but the vast majority of existing quoting was done with double
quotes, so move in that direction.

Bug: http://b/27524191
Change-Id: I8f58593120e4c8aeaec45e16fc0178e9c162454d
diff --git a/linker/linker_mips.cpp b/linker/linker_mips.cpp
index 6130066..2d565d7 100644
--- a/linker/linker_mips.cpp
+++ b/linker/linker_mips.cpp
@@ -67,7 +67,7 @@
     ElfW(Addr) sym_addr = 0;
     const char* sym_name = nullptr;
 
-    DEBUG("Processing '%s' relocation at index %zd", get_realpath(), idx);
+    DEBUG("Processing \"%s\" relocation at index %zd", get_realpath(), idx);
     if (type == R_GENERIC_NONE) {
       continue;
     }