Netconsole loses the second character when used as input by
either setenv stdin nc or setenv stdin serial,nc if using CONSOLE_CONSOLE_MUX

Before a nc_send_packet() to echo the input, a check is done to see if
nc_ether is valid. If its not, it waits for an arp request and then sends
the packet (which contains the first character of line to be displayed as
output). As part of reaping the arp request, the second character is consumed.
We protect this by making the call to NetLoop(NETCONS) between
input_recursion.

Signed-off-by: Suriyan Ramasami <suriyan.r@gmail.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>