t0050: perl portability fix

Older versions of perl (such as 5.005) don't understand -CO, nor
do they understand the "U" pack specifier. Instead of using perl,
let's just printf the binary bytes we are interested in.

Signed-off-by: Jeff King <peff@peff.net>
Tested-by: Johannes Sixt <johannes.sixt@telecom.at>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t0050-filesystem.sh

@@ -4,8 +4,8 @@ test_description='Various filesystem issues'
 
 . ./test-lib.sh
 
-auml=`perl -CO -e 'print pack("U",0x00E4)'`
-aumlcdiar=`perl -CO -e 'print pack("U",0x0061).pack("U",0x0308)'`
+auml=`printf '\xc3\xa4'`
+aumlcdiar=`printf '\x61\xcc\x88'`
 
 test_expect_success 'see if we expect ' '