module: fix a memory leak
module: fix a memory leak

When a module is removed and re-inserted without unrefing, the
kmod_file is unconditionally re-opened. This results in a memory
and file descriptor leak.

Fix it by checking if the file is already open in
kmod_module_insert_module().

Signed-off-by: Bartosz Golaszewski <e5d45fddd9040473413b909b802f629a971ad04c@baylibre.com>

pmmccorm/kmod,lucasdemarchi/kmod,pmmccorm/kmod,lucasdemarchi/kmod,pmmccorm/kmod,lucasdemarchi/kmod