nfsd4: fix missing fault_inject.h include

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index d10ad8b..fddb18b 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -44,6 +44,7 @@
 #include "xdr4.h"
 #include "vfs.h"
 #include "current_stateid.h"
+#include "fault_inject.h"
 
 #define NFSDDBG_FACILITY                NFSDDBG_PROC