net-snmp: initscripts are located in net-snmp-server-snmp package

The net-snmp-server package is a meta-package requiring
net-snmp-server-snmpd and net-snmp-server-snmptrapd package.
The net-snmp-server-snmpd package provides the startup scripts
not the meta net-snmp-server package.

Signed-off-by: Anders Wallin <anders.wallin@windriver.com>
Signed-off-by: Li Wang <li.wang@windriver.com>
Signed-off-by: Jackie Huang <jackie.huang@windriver.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
Signed-off-by: Joe MacDonald <joe_macdonald@mentor.com>
(cherry picked from commit 4fbb4d2371648ceb9ad6b99f46261ed5a125fb98)
Signed-off-by: Armin Kuster <akuster808@gmail.com>