Fix test script error codes

The 'exit $?' command in the INT TERM EXIT trap was overwritting
the expected error code with the error code from mv.  Fix the
issue by removing the 'exit $?'.  It's important the we preserve
the original error code so failures are easily noticed.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>

scripts/common.sh.in

@@ -124,7 +124,7 @@ init() {
 	# set to ensure the udev rule is correctly replaced on exit.
 	local RULE=${udevruledir}/90-zfs.rules
 	if test -e  ${RULE}; then
-		trap "mv ${RULE}.disabled ${RULE}; exit $?" INT TERM EXIT
+		trap "mv ${RULE}.disabled ${RULE}" INT TERM EXIT
 		mv ${RULE} ${RULE}.disabled
 	fi
 }