FAQ: Document 'Resource busy' error in FAQ
FAQ: Document 'Resource busy' error in FAQ

Document 'Resource busy' error cause and possible remedial in
FAQ documentation.

Fixes: #1109

Signed-off-by: Abhijeet Kasurde <6334fd0c217b1f2a15926284df229acde5b4fc3a@redhat.com>

firecracker-microvm/firecracker,firecracker-microvm/firecracker,firecracker-microvm/firecracker,firecracker-microvm/firecracker,firecracker-microvm/firecracker