test_firmware: wrap sysfs timeout test into helper

This cannot run on all kernel builds. This will help us later
skip this test on kernel configs where non-applicable.
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tools/testing/selftests/firmware/fw_fallback.sh

@@ -175,16 +175,18 @@ trap "test_finish" EXIT
 echo "ABCD0123" >"$FW"
 NAME=$(basename "$FW")
 
-DEVPATH="$DIR"/"nope-$NAME"/loading
+test_syfs_timeout()
+{
+	DEVPATH="$DIR"/"nope-$NAME"/loading
 
-# Test failure when doing nothing (timeout works).
-echo -n 2 >/sys/class/firmware/timeout
-echo -n "nope-$NAME" >"$DIR"/trigger_request 2>/dev/null &
+	# Test failure when doing nothing (timeout works).
+	echo -n 2 >/sys/class/firmware/timeout
+	echo -n "nope-$NAME" >"$DIR"/trigger_request 2>/dev/null &
 
-# Give the kernel some time to load the loading file, must be less
-# than the timeout above.
-sleep 1
-if [ ! -f $DEVPATH ]; then
+	# Give the kernel some time to load the loading file, must be less
+	# than the timeout above.
+	sleep 1
+	if [ ! -f $DEVPATH ]; then
 		echo "$0: fallback mechanism immediately cancelled"
 		echo ""
 		echo "The file never appeared: $DEVPATH"
@@ -200,14 +202,17 @@ if [ ! -f $DEVPATH ]; then
 		echo "If you do remove this file or comment out this line before"
 		echo "proceeding with these tests."
 		exit 1
-fi
+	fi
 
-if diff -q "$FW" /dev/test_firmware >/dev/null ; then
+	if diff -q "$FW" /dev/test_firmware >/dev/null ; then
 		echo "$0: firmware was not expected to match" >&2
 		exit 1
-else
+	else
 		echo "$0: timeout works"
-fi
+	fi
+}
+
+test_syfs_timeout
 
 # Put timeout high enough for us to do work but not so long that failures
 # slow down this test too much.