kmod: fixed cross-compiling by explicitely running autoreconf

Note:

This fixes an issue discovered when building on a Fedora 16 build host.

Snippet from the build log
-----------------------------------------------------------------------------
  GEN      tools/insmod
  GEN      tools/rmmod
  GEN      tools/lsmod
  GEN      tools/modprobe
  GEN      tools/modinfo
  GEN      tools/depmod
/lib/libpthread.so.0: undefined reference to `__getrlimit@GLIBC_PRIVATE'
/lib/libpthread.so.0: undefined reference to `__uname@GLIBC_PRIVATE'
collect2: error: ld returned 1 exit status
make[2]: *** [tools/kmod] Error 1
make[1]: *** [all-recursive] Error 1
make: *** [all] Error 2
-----------------------------------------------------------------------------

base/kmod/kmod.conf

@@ -15,6 +15,9 @@
 prefix=
 set_confopt
 
+# always regenerate autotools files
+hook_add preconf 9 'autoreconf -vfi'
+
 # always build a static library
 var_append extraconfopt ' ' "--enable-static"