src/manifest: fix manifest leaking on error in parse_manifest()
src/manifest: fix manifest leaking on error in parse_manifest()

Fixes coverity issue:
| CID 1445506 (#1 of 1): Resource leak (RESOURCE_LEAK)
| 7. leaked_storage: Variable raucm going out of scope leaks the storage it points to

Signed-off-by: Enrico Joerns <a2e5f936c390f36494e46e71bcfbe365bb1e8c49@pengutronix.de>

jluebbe/rauc,jluebbe/rauc,ejoerns/rauc,rauc/rauc,rauc/rauc,ejoerns/rauc,jluebbe/rauc,rauc/rauc,ejoerns/rauc