um: Do not use stdin and stdout identifiers for struct members

stdin, stdout and stderr are macros according to C89/C99.
Thus do not use them as struct member identifiers to avoid
bad results from macro expansion.

Signed-off-by: Hans-Werner Hilse <hwhilse@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

diff --cc arch/um/drivers/harddog_user.c
Simple merge

diff --cc arch/um/drivers/net_user.c
Simple merge

diff --cc arch/um/drivers/slip_user.c
Simple merge

diff --cc arch/um/drivers/slirp_user.c
Simple merge

diff --cc arch/um/os-Linux/drivers/tuntap_user.c
Simple merge