dracut: fix core module path

Forgot to update this file when moving the core module to the extras
subdirectory with a6694ffffff879b1255332e3b03e00b61630fa52.
Merge pull request #195 from jpoimboe/initramfs-core-module-path

dracut: fix core module path
kmod/patch: export patched functions information via sysfs

This feature is implemented as:
```
[root@localhost kpatch]# insmod ./kpatch-meminfo.ko
[root@localhost kpatch]# ls /sys/kernel/kpatch/patches/kpatch_meminfo/functions/meminfo_proc_show/
new_addr  old_addr
[root@localhost kpatch]# cat /sys/kernel/kpatch/patches/kpatch_meminfo/functions/meminfo_proc_show/new_addr
0xffffffffa05211e0
[root@localhost kpatch]# cat /sys/kernel/kpatch/patches/kpatch_meminfo/functions/meminfo_proc_show/old_addr
0xffffffff8125d0e0
```

During patch module init, alloc and init kpatch_func_obj with customized
kobj_type patch_func_ktype. The attribute new_addr and old_addr is attached to
patch_func_ktype, so that these files could be created by kobject_add.

Signed-off-by: Jincheng Miao <jincheng.miao@gmail.com>