helper/bin2char: drop trailing empty line

For unknown reasons, the coreutils tool 'od' on MacOS outputs an
extra empty line, which appears in the new auto-generated files.

Modify the script bin2char.sh to drop every empty line.

Change-Id: Id835fecadb58ad4ddfc11ef9f9a2e8d75c5dffe9
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/8051
Reviewed-by: Erhan Kurubas <erhan.kurubas@espressif.com>
Tested-by: jenkins
Reviewed-by: Henrik Nordström <henrik.nordstrom@addiva.se>

src/helper/bin2char.sh

@@ -12,4 +12,4 @@
 }
 
 echo "/* Autogenerated with $0 */"
-od -v -A n -t x1 | sed 's/ *\(..\) */0x\1,/g'
+od -v -A n -t x1 | sed 's/ *\(..\) */0x\1,/g;/^$/d'