selftests: firmware: send expected errors to /dev/null

Error that we expect should not be spilled to stdout.

Without this we get:

./fw_filesystem.sh: line 58: printf: write error: Invalid argument
./fw_filesystem.sh: line 63: printf: write error: No such device
./fw_filesystem.sh: line 69: echo: write error: No such file or directory
./fw_filesystem.sh: filesystem loading works
./fw_filesystem.sh: async filesystem loading works

With it:

./fw_filesystem.sh: filesystem loading works
./fw_filesystem.sh: async filesystem loading works
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tools/testing/selftests/firmware/fw_filesystem.sh

@@ -63,18 +63,18 @@ echo "ABCD0123" >"$FW"
 
 NAME=$(basename "$FW")
 
-if printf '\000' >"$DIR"/trigger_request; then
+if printf '\000' >"$DIR"/trigger_request 2> /dev/null; then
 	echo "$0: empty filename should not succeed" >&2
 	exit 1
 fi
 
-if printf '\000' >"$DIR"/trigger_async_request; then
+if printf '\000' >"$DIR"/trigger_async_request 2> /dev/null; then
 	echo "$0: empty filename should not succeed (async)" >&2
 	exit 1
 fi
 
 # Request a firmware that doesn't exist, it should fail.
-if echo -n "nope-$NAME" >"$DIR"/trigger_request; then
+if echo -n "nope-$NAME" >"$DIR"/trigger_request 2> /dev/null; then
 	echo "$0: firmware shouldn't have loaded" >&2
 	exit 1
 fi