net: vrf: replace hard tab with space in assignment

The assignment of rth->dst.output in vrf_rt6_create() and
vrf_rtable_create() used a hard tab before the '='. The neighboring
assignments did not. Make the assignment of rth->dst.output consistent
with the surrounding code.
Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Acked-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>