aprwatch: Add path for sendmail

Arpwatch won't build on a system without a sendmail provider
installed with out this setting.

Signed-off-by: Jeremy A. Puhlman <jpuhlman@mvista.com>
Signed-off-by: Armin Kuster <akuster808@gmail.com>

recipes-scanners/arpwatch/arpwatch_3.3.bb

@@ -42,6 +42,7 @@ CONFIGUREOPTS = " --build=${BUILD_SYS} \
           --infodir=${infodir} \
           --mandir=${mandir} \
           --srcdir=${S} \
+          --with-sendmail=${sbindir}/sendmail \
           "
 
 do_configure () {