staging: ramster: depend on NET for sock_* functions

Building ramster without NET would cause linkage issue due to missing
sock_*() functions in cluster/tcp.c
Signed-off-by: NSasha Levin <levinsasha928@gmail.com>
Acked-by: NDan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/ramster/Kconfig

 config RAMSTER
 	bool "Cross-machine RAM capacity sharing, aka peer-to-peer tmem"
-	depends on (CLEANCACHE || FRONTSWAP) && CONFIGFS_FS=y && !ZCACHE && !XVMALLOC && !HIGHMEM
+	depends on (CLEANCACHE || FRONTSWAP) && CONFIGFS_FS=y && !ZCACHE && !XVMALLOC && !HIGHMEM && NET
 	select LZO_COMPRESS
 	select LZO_DECOMPRESS
 	default n