MokManager: Try APPEND_WRITE first
MokManager: Try APPEND_WRITE first

Try to append the MOK/MOKX list first and then fallback to the normal
SetVariable if the firmware doesn't support EFI_VARIABLE_APPEND_WRITE.

Signed-off-by: Gary Lin <a057d4b27e9e9055b973f54b519db54c22ed5ee8@suse.com>

rhinstaller/shim,rhinstaller/shim,rhinstaller/shim