slcanpty: fix wrong usage of nbytes variable
slcanpty: fix wrong usage of nbytes variable

nbytes is used after writing the CAN frame to check for an additional command
in the string buffer. Therefore using nbytes while writing the CAN frame is
wrong. Replace it with 'tmp' which can be used here without problems.

Signed-off-by: ulrich escher<46f1a0bd5592a2f9244ca321b129902a06b53e03@myvdr.de>
Signed-off-by: Oliver Hartkopp <06a38fb2ed1a2d0a17f4f06761ac2e5ace5a31ab@hartkopp.net>

carloop/can-utils-osx,carloop/can-utils-osx