media: rc: imon: replace strcpy() by strscpy()

The strcpy() function is being deprecated. Replace it by the
safer strscpy().

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>