core: proc_cmdline_params: Fix-up broken --tgt-fs parsing

`tr` requires input from the standard input device, instead of from
commandline argument.  This patch fixes the command by using the "Here
Strings" redirection feature.

Fixes #210.

Reported-by: mishka81 <https://github.com/mishka81>
Refer-to: --tgt-fs option does not work · Issue #210 · slacka/WoeUSB
<https://github.com/slacka/WoeUSB/issues/210>
Blame: WoeUSB/woeusb at 2c7c039 ·
slacka/WoeUSB
<https://github.com/slacka/WoeUSB/blob/2c7c03954012eb129bcf473d6786643482a61da9/src/woeusb#L583-L586>
Signed-off-by: 林博仁(Buo-ren Lin) <[email protected]>

src/woeusb

@@ -583,7 +583,7 @@ process_commandline_parameters(){
 					tr \
 						'[:lower:]' \
 						'[:upper:]' \
-					"${parameters[0]}"
+					<<< "${parameters[0]}"
 				)"
 				;;
 			*)