Most of the codebase as been converted to use glib memory allocation
functions.  There are still a few instances of malloc/calloc in the
block layer and qemu-io.  Replace them, especially since they do not
check the strdup/malloc/calloc return value.
Reported-by: NDr David Alan Gilbert <davidagilbert@uk.ibm.com>
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>