fold fifo.c into pipe.c

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/Makefile b/fs/Makefile
index 9d53192..b691a96 100644
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -7,7 +7,7 @@
 
 obj-y :=	open.o read_write.o file_table.o super.o \
 		char_dev.o stat.o exec.o pipe.o namei.o fcntl.o \
-		ioctl.o readdir.o select.o fifo.o dcache.o inode.o \
+		ioctl.o readdir.o select.o dcache.o inode.o \
 		attr.o bad_inode.o file.o filesystems.o namespace.o \
 		seq_file.o xattr.o libfs.o fs-writeback.o \
 		pnode.o drop_caches.o splice.o sync.o utimes.o \