intel/skylake: Enable signalling of error condition

Testing for "devfn < 0" on an unsigned doesn't work, and i2c_bus_to_devfn
returns an int (with -1 for "error"), so use int for devfn.

Change-Id: I7d1cdb6af4140f7dc322141c0c018d8418627434
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Found-by: Coverity Scan #1357450, #1357449
Reviewed-on: https://review.coreboot.org/15964
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
1 file changed