MokManager: avoid -Werror=address-of-packed-member
MokManager: avoid -Werror=address-of-packed-member

When compiling with GCC 9, there are a couple of errors of the form

MokManager.c: In function ‘write_back_mok_list’:
MokManager.c:1056:19: error: taking address of packed member of ‘struct <anonymous>’ may result in an unaligned pointer value [-Werror=address-of-packed-member]
 1056 |   if (CompareGuid(&(list[i].Type), &X509_GUID) == 0)
      |                   ^~~~~~~~~~~~~~~

Copying the member of the packed struct to a temporary variable and
pointing to that variable solves the problem.

Upstream-commit-id: 58532e12e9a

rhinstaller/shim,rhinstaller/shim,rhinstaller/shim