sysctl: set variable key_sysctls storage-class-specifier to static

smatch reports
security/keys/sysctl.c:12:18: warning: symbol
  'key_sysctls' was not declared. Should it be static?

This variable is only used in its defining file, so it should be static.
Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>

security/keys/sysctl.c

@@ -9,7 +9,7 @@
 #include <linux/sysctl.h>
 #include "internal.h"
 
-struct ctl_table key_sysctls[] = {
+static struct ctl_table key_sysctls[] = {
 	{
 		.procname = "maxkeys",
 		.data = &key_quota_maxkeys,