Clean up warnings in stubs.cpp.

Switch to C++ to get extra warnings, and format the code Google style.

Change-Id: Ifc0131bf297a6ee8a8a6b8d049a02518b0b1a4b7
diff --git a/libc/Android.mk b/libc/Android.mk
index 26da523..d0c9218 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -292,7 +292,7 @@
 	bionic/sched_cpucount.c \
 	bionic/semaphore.c \
 	bionic/sha1.c \
-	bionic/stubs.c \
+	bionic/stubs.cpp \
 	bionic/system_properties.c \
 	bionic/tdelete.c \
 	bionic/tdestroy.c \