linuxkm fedora: fix uninitialized build errors.

[philljj]

Description

Fix build errors when building linuxkm on Fedora:

/home/jordan/work/wolfssl/wolfcrypt/src/misc.c:1012:12: error: ‘_in’ may be used uninitialized [-Werror=maybe-uninitialized]
 1012 |     word64 _in;
      |            ^~~
cc1: all warnings being treated as errors

Note: these build errors appear on some kernels but not others, even when using the same gcc. Presumably because of differences in .config.

[philljj]

Retest this please.

Found unhandled org.jenkinsci.plugins.workflow.support.steps.AgentOfflineException exception:
...