fel-gpio: Fail on errors after initialization as well

fel-gpio

-#!/bin/sh
+#!/bin/sh -e
 
 pio_to_sram=0x2000
 sram_to_pio=0x2004
 
-set -e
 if [ -f fel-pio.bin ]; then
 	./fel write 0x2000 fel-pio.bin
 else
@@ -15,7 +14,6 @@ fi
 ./pio -i pio.reg print > pio.old
 cat pio.old | fgrep -v '<0><0><0><0>'
 
-set +e
 while read cmd; do
 	./pio -i pio.reg -o pio.reg $cmd
 	./fel write 0x3000 pio.reg
@@ -23,6 +21,6 @@ while read cmd; do
 	./fel exe 0x2000
 	./fel read 0x3000 0x228 pio.reg
 	./pio -i pio.reg print > pio.new
-	diff -U0 pio.old pio.new
+	diff -U0 pio.old pio.new || true
 	mv -f pio.new pio.old
 done