NFSD: Fix sparse warning in nfssvc.c

fs/nfsd/nfssvc.c:36:6: warning: symbol 'inter_copy_offload_enable' was not declared. Should it be static?

The parameter was added by commit ce0887ac ("NFSD add nfs4 inter
ssc to nfsd4_copy"). Relocate it into the source file that uses it,
and make it static. This approach is similar to the
nfs4_disable_idmapping, cltrack_prog, and cltrack_legacy_disable
module parameters.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

fs/nfsd/nfs4proc.c

@@ -50,6 +50,11 @@
 #include "pnfs.h"
 #include "trace.h"
 
+static bool inter_copy_offload_enable;
+module_param(inter_copy_offload_enable, bool, 0644);
+MODULE_PARM_DESC(inter_copy_offload_enable,
+		 "Enable inter server to server copy offload. Default: false");
+
 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
 #include <linux/security.h>
 

fs/nfsd/nfssvc.c

@@ -33,12 +33,6 @@
 
 #define NFSDDBG_FACILITY	NFSDDBG_SVC
 
-bool inter_copy_offload_enable;
-EXPORT_SYMBOL_GPL(inter_copy_offload_enable);
-module_param(inter_copy_offload_enable, bool, 0644);
-MODULE_PARM_DESC(inter_copy_offload_enable,
-		 "Enable inter server to server copy offload. Default: false");
-
 extern struct svc_program	nfsd_program;
 static int			nfsd(void *vrqstp);
 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)

fs/nfsd/xdr4.h

@@ -568,7 +568,6 @@ struct nfsd4_copy {
 	struct nfs_fh		c_fh;
 	nfs4_stateid		stateid;
 };
-extern bool inter_copy_offload_enable;
 
 struct nfsd4_seek {
 	/* request */