alpha: Don't export SOCK_NONBLOCK to user space.

Currently we export SOCK_NONBLOCK to user space but that conflicts with
the definition from glibc leading to compilation errors in user programs
(e.g. see Debian bug #658460).

The generic socket.h restricts the definition of SOCK_NONBLOCK to the
kernel, as does the MIPS specific socket.h, so let's do the same on
Alpha.

Signed-off-by: Michael Cree <[e-mail]>
Acked-by: Matt Turner <[e-mail]>
Cc: [e-mail]
Signed-off-by: Linus Torvalds <[e-mail]>

arch/alpha/include/asm/socket.h

···
 /* Instruct lower device to use last 4-bytes of skb data as FCS */
 #define SO_NOFCS		43
 
+#ifdef __KERNEL__
 /* O_NONBLOCK clashes with the bits used for socket types.  Therefore we
  * have to define SOCK_NONBLOCK to a different value here.
  */
 #define SOCK_NONBLOCK	0x40000000
+#endif /* __KERNEL__ */
 
 #endif /* _ASM_SOCKET_H */