nfsd: use ARRAY_SIZE

Using the ARRAY_SIZE macro improves the readability of the code.

Found with Coccinelle with the following semantic patch:
@r depends on (org || report)@
type T;
T[] E;
position p;
@@
(
 (sizeof(E)@p /sizeof(*E))
|
 (sizeof(E)@p /sizeof(E[...]))
|
 (sizeof(E)@p /sizeof(T))
)

Signed-off-by: Jérémy Lefaure <jeremy.lefaure@lse.epita.fr>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

fs/nfsd/fault_inject.c

@@ -11,6 +11,7 @@
 #include <linux/nsproxy.h>
 #include <linux/sunrpc/addr.h>
 #include <linux/uaccess.h>
+#include <linux/kernel.h>
 
 #include "state.h"
 #include "netns.h"
@@ -125,8 +126,6 @@ static struct nfsd_fault_inject_op inject_ops[] = {
 	},
 };
 
-#define NUM_INJECT_OPS (sizeof(inject_ops)/sizeof(struct nfsd_fault_inject_op))
-
 int nfsd_fault_inject_init(void)
 {
 	unsigned int i;
@@ -137,7 +136,7 @@ int nfsd_fault_inject_init(void)
 	if (!debug_dir)
 		goto fail;
 
-	for (i = 0; i < NUM_INJECT_OPS; i++) {
+	for (i = 0; i < ARRAY_SIZE(inject_ops); i++) {
 		op = &inject_ops[i];
 		if (!debugfs_create_file(op->file, mode, debug_dir, op, &fops_nfsd))
 			goto fail;