Honor VMFORMATS and VMSIZE if set in release.conf.

PR:		203420
Submitted by:	luca <dot> pizzamiglio <at> gmail <dot> com
MFC after:	3 days
Sponsored by:	The FreeBSD Foundation

release/release.sh

@@ -208,6 +208,7 @@ env_check() {
 	RELEASE_RMAKEFLAGS="${ARCH_FLAGS} \
 		KERNCONF=\"${KERNEL}\" ${CONF_FILES} ${DOCPORTS} \
 		WITH_DVD=${WITH_DVD} WITH_VMIMAGES=${WITH_VMIMAGES} \
+		VMFORMATS=\"${VMFORMATS}\" VMSIZE=${VMSIZE} \
 		WITH_CLOUDWARE=${WITH_CLOUDWARE} XZ_THREADS=${XZ_THREADS}"
 
 	return 0