net-snmp: add symlink for net-snmp-config into usr/bin

A lot of autoconf-based scripts expect --with-foo-dir=$(STAGING_DIR)/usr
and break if they can't find bin/foo-config as a child of that path.

Putting things in $(STAGING_DIR)/host/bin seems to be suboptimal; I
could change the install path but there's no saying what that would
break.

Signed-off-by: Philip Prindeville <philipp@redfish-solutions.com>

net/net-snmp/Makefile

@@ -209,6 +209,7 @@ define Build/InstallDev
 	$(INSTALL_DIR) $(2)/bin
 	$(INSTALL_BIN) $(PKG_INSTALL_DIR)/usr/bin/net-snmp-config $(2)/bin/
 	$(SED) 's,=/usr,=$(STAGING_DIR)/usr,g' $(2)/bin/net-snmp-config
+	$(LN) $(STAGING_DIR)/host/bin/net-snmp-config $(STAGING_DIR)/usr/bin/
 
 	$(INSTALL_DIR) $(1)/usr/include
 	$(CP) $(PKG_INSTALL_DIR)/usr/include/net-snmp $(1)/usr/include/