Fixing RedHat service name

In RedHat 5 and 6, the samba service name is smb.

RedHat 5: https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Linux/5/html/Deployment_Guide/s1-samba-daemons.html

RedHat 6: https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Deployment_Guide/ch-File_and_Print_Servers.html#s2-samba-daemons