modules: mark __inittest/__exittest as __maybe_unused

clang warns about unused inline functions by default:

arch/arm/crypto/aes-cipher-glue.c:68:1: warning: unused function '__inittest' [-Wunused-function]
arch/arm/crypto/aes-cipher-glue.c:69:1: warning: unused function '__exittest' [-Wunused-function]

As these appear in every single module, let's just disable the warnings by marking the
two functions as __maybe_unused.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jessica Yu <jeyu@redhat.com>

include/linux/module.h

@@ -127,13 +127,13 @@ extern void cleanup_module(void);
 
 /* Each module must use one module_init(). */
 #define module_init(initfn)					\
-	static inline initcall_t __inittest(void)		\
+	static inline initcall_t __maybe_unused __inittest(void)		\
 	{ return initfn; }					\
 	int init_module(void) __attribute__((alias(#initfn)));
 
 /* This is only required if you want to be unloadable. */
 #define module_exit(exitfn)					\
-	static inline exitcall_t __exittest(void)		\
+	static inline exitcall_t __maybe_unused __exittest(void)		\
 	{ return exitfn; }					\
 	void cleanup_module(void) __attribute__((alias(#exitfn)));