powerpc/module_64: fix array_size.cocci warning

Fix following coccicheck warning:
./arch/powerpc/kernel/module_64.c:432:40-41: WARNING: Use ARRAY_SIZE.

ARRAY_SIZE(arr) is a macro provided by the kernel. It makes sure that arr
is an array, so it's safer than sizeof(arr) / sizeof(arr[0]) and more
standard.
Signed-off-by: Guo Zhengkui <guozhengkui@vivo.com>
Reviewed-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220223075426.20939-1-guozhengkui@vivo.com

arch/powerpc/kernel/module_64.c

@@ -14,6 +14,7 @@
 #include <linux/ftrace.h>
 #include <linux/bug.h>
 #include <linux/uaccess.h>
+#include <linux/kernel.h>
 #include <asm/module.h>
 #include <asm/firmware.h>
 #include <asm/code-patching.h>
@@ -429,7 +430,7 @@ static inline int create_stub(const Elf64_Shdr *sechdrs,
 	if (is_mprofile_ftrace_call(name))
 		return create_ftrace_stub(entry, addr, me);
 
-	for (i = 0; i < sizeof(ppc64_stub_insns) / sizeof(u32); i++) {
+	for (i = 0; i < ARRAY_SIZE(ppc64_stub_insns); i++) {
 		if (patch_instruction(&entry->jump[i],
 				      ppc_inst(ppc64_stub_insns[i])))
 			return 0;