tests: improve unbuffer check

* remove obsolete stdbuf check

* check for unbuffer command in ts_run() than skip all test

Reported-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Karel Zak <kzak@redhat.com>

tests/functions.sh

@@ -425,7 +425,7 @@ function ts_run {
 	while true; do
 		case "$1" in
 			--unbuffered)
-				if type stdbuf >/dev/null 2>&1; then
+				if type unbuffer >/dev/null 2>&1; then
 					UNBUFFERED=1
 				fi
 				shift;;

tests/ts/libfdisk/mkpart-full

@@ -27,7 +27,6 @@ TESTPROG="$TS_HELPER_LIBFDISK_MKPART_FULLSPEC"
 ts_check_test_command "$TESTPROG"
 ts_check_test_command "$TS_CMD_SFDISK"
 ts_check_test_command "$TS_CMD_WIPEFS"
-ts_check_prog unbuffer
 
 TEST_IMAGE_NAME=$(ts_image_init 15)
 

tests/ts/misc/swaplabel

@@ -21,7 +21,6 @@ ts_init "$*"
 ts_check_test_command "$TS_CMD_MKSWAP"
 ts_check_test_command "$TS_CMD_SWAPLABEL"
 ts_check_test_command "$TS_HELPER_SYSINFO"
-ts_check_prog unbuffer
 
 # fallocate does not work on most file systems
 function fallocate_or_skip()

tests/ts/rename/exit_codes

@@ -22,7 +22,6 @@ TS_DESC="exit codes"
 ts_init "$*"
 
 ts_check_test_command "$TS_CMD_RENAME"
-ts_check_prog unbuffer
 
 ts_cd "$TS_OUTDIR"