TODO: Add some entries
Fix coding style

Either with space or without, not a mix of both.
missing: Don't call syscall() with syscallno == -1

Reported-by: Jean-Francis Roy <jeanfrancis@funtoo.org>
Reported-by: Jan Luebbe <jlu@pengutronix.de>
modprobe: don't check refcount with remove command

The modprobe.d (5) documentation for the "install" command
states that you could specify

install fred /sbin/modprobe barney; /sbin/modprobe --ignore-install fred

This makes some sense, but then the loading of "barney" is
hidden from the user who did only "modprobe fred". Thus,
it seems it should be possible to be able to unload the
"fred" module with "modprobe -r fred" by configuring the
"barney" module to also be removed:

remove fred /sbin/rmmod barney fred

(or similar.)

Make this possible by not checking the refcount when an
unload command was configured.

Reported-by: David Spinadel <david.spinadel@intel.com>
Several minor fixes for documentation
Add document for exported enums

There are several exported enums by libkmod without document, this patch
mainly added documentation for below enums like the way kmod_resources
be documented in.
* kmod_index
* kmod_remove
* kmod_insert
* kmod_probe
* kmod_filter
* kmod_module_initstate

This is not the best way to document these exported enums, however, it's
the simple way due to gtkdoc limits. It doesn't support export plain
enum like below: see https://bugzilla.gnome.org/show_bug.cgi?id=657444
---------8<-------head.h--------------8<-----------
...
enum foo {
    ...
};
...
---------8<-------end of head.h-------8<-----------
---------8<-------source.c------------8<-----------
...
/**
 * document for foo here
 */
...
typedef enum foo foo;
...
---------8<-------end of source.c-----8<----------
Revert "missing: Don't call syscall() with syscallno == -1"

This reverts commit 38829712e5c411bc250aeae142fc6bf06e794d58.  It fixes
the problem, but it breaks the testsuite for those who don't have
__NR_finit_module. The testsuite would have to make the same check.

Instead, I'm reverting this change and I'm going to apply another patch
from Jan Luebbe who got this right from the beginning.
libkmod: Avoid calling syscall() with -1

At least in qemu 1.4.1 for vexpress/arm-cortexa9, this resulted in an
illegal instruction error. Solve that by returning an error when
__NR_finit_module is -1.
Add travis config file