[PCOUNTER] Fix build error without CONFIG_SMP

I keep getting this build error and couldn't find anyone fixing
it in archives. ...Maybe all net developers except me build
just SMP kernels :-).

In file included from include/net/sock.h:50,
                 from ipc/mqueue.c:35:
include/linux/pcounter.h: In function 'pcounter_add':
include/linux/pcounter.h:87: error: 'struct pcounter' has no
member named 'value'
make[1]: *** [ipc/mqueue.o] Error 1
make: *** [ipc] Error 2
Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Acked-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/linux/pcounter.h

@@ -84,7 +84,7 @@ static inline int pcounter_getval(const struct pcounter *self)
 
 static inline void pcounter_add(struct pcounter *self, int inc)
 {
-	self->value += inc;
+	self->val += inc;
 }
 
 static inline int pcounter_getval(const struct pcounter *self)