Do not abort on qemu_malloc(0) in production builds

Do not abort on qemu_malloc(0) in production builds

qemu_malloc() does not allow size=0 to be passed in and aborts on this behavior.

Unfortunately, there is good reason to believe that within qemu, there are a
number of, so far, undetected places that assume size=0 can be safely passed.
Since we do not want to abort unnecessarily in production builds, return
qemu_malloc(1) whenever the version file indicates that this is a production
build.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>