Fix sysfs mount in net_test.sh.

The new net_test.sh used by build_rootfs.sh used a broken filesystem
type for sysfs. This meant that sysfs was not mounted. This did not
actually break anything because sysfs does not appear to be used by the
tests.

Bug: 79694505
Test: run_net_test.sh all_tests.sh
Change-Id: I781902d5561f5d7a9815cd886f30bf7d27bf996e
Signed-off-by: Alistair Strachan <astrachan@google.com>
diff --git a/net/test/rootfs/net_test.sh b/net/test/rootfs/net_test.sh
index 072a8a3..9c94d06 100755
--- a/net/test/rootfs/net_test.sh
+++ b/net/test/rootfs/net_test.sh
@@ -16,7 +16,7 @@
 #
 
 mount -t proc none /proc
-mount -t sys none /sys
+mount -t sysfs none /sys
 mount -t tmpfs tmpfs /tmp
 mount -t tmpfs tmpfs /run