net/smc: replace strncpy with strscpy

Replace the deprecated strncpy() with two-argument version of
strscpy() as the destination is an array
and should be NUL-terminated.

Signed-off-by: Pranav Tyagi <pranav.tyagi03@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250620102559.6365-1-pranav.tyagi03@gmail.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>