Linter warnings even though syntax is correct

[Gerrit91]

The following instruction should be correct:

RUN test "${PKGMGR}" == "yum" \
 && (grep -E "^localpkg_gpgcheck=1" /etc/yum.conf \
 || echo "localpkg_gpgcheck=1" >> /etc/yum.conf) \
 || test "${PKGMGR}" != "yum"

But leads to:

$ docker-make -sl 
Step 0 : Linting "./Dockerfile" 
---> \[WARNING\] AND (&&) / OR (||) control operators must be in front of each concerned line for multi-line RUN commands (rule11_0, line: 40) 
---> \[WARNING\] AND (&&) / OR (||) control operators should be indented by a single white space in front of each concerned line for multi-line RUN commands (rule11_1, line: 40)
---> OK with warning(s)