Revert "kmod-setup: don't print warning on -ENOSYS"

This partially reverts commit 78d298b.
The changed coding-style is kept, but the ENOENT->ENOSYS conversion is
reverted.

kmod was fixed upstream to no longer return ENOSYS. Also see:
    https://git.kernel.org/cgit/utils/kernel/kmod/kmod.git/commit/?id=114ec87c85c35a2bd3682f9f891e494127be6fb5

The kmod fix is marked for backport, so no reason to bump the kmod
version we depend on.

Author: David Herrmann

src/core/kmod-setup.c

@@ -116,7 +116,7 @@ int kmod_setup(void) {
                 else if (r == KMOD_PROBE_APPLY_BLACKLIST)
                         log_info("Module '%s' is blacklisted", kmod_module_get_name(mod));
                 else {
-                        bool print_warning = kmod_table[i].warn_if_unavailable || (r < 0 && r != -ENOSYS);
+                        bool print_warning = kmod_table[i].warn_if_unavailable || (r < 0 && r != -ENOENT);
 
                         log_full_errno(print_warning ? LOG_WARNING : LOG_DEBUG, r,
                                        "Failed to insert module '%s': %m", kmod_module_get_name(mod));