Revert "tools/vm: fix page-flags build"

This reverts commit 2f2c08d6, which was
commit 4933f55f upstream.

This patch is not suitable for kernel 3.16 as running 'make -C tools/vm'
will result in a build failure.
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

tools/vm/Makefile

@@ -3,7 +3,7 @@
 TARGETS=page-types slabinfo
 
 LIB_DIR = ../lib/api
-LIBS = $(LIB_DIR)/libapi.a
+LIBS = $(LIB_DIR)/libapikfs.a
 
 CC = $(CROSS_COMPILE)gcc
 CFLAGS = -Wall -Wextra -I../lib/