NarUtil: handle null Linker parameter top getAOL(...) as intended
NarUtil: handle null Linker parameter top getAOL(...) as intended

Previously we were throwing a NullPointerException if we had a null
Linker passed in, because of the line:
    if(linker != null & linker.getName() != null)

This change simply changes that single-ampersand to a double-ampersand
which is the behaviour the original author intended.

heathn/nar-maven-plugin,maven-nar/nar-maven-plugin,maven-nar/nar-maven-plugin,heathn/nar-maven-plugin,heathn/nar-maven-plugin,maven-nar/nar-maven-plugin,maven-nar/nar-maven-plugin,heathn/nar-maven-plugin,heathn/nar-maven-plugin,maven-nar/nar-maven-plugin