[PATCH] selftests/ftrace: Quote check_requires comparisons

[Cao Ruichuang <create0818@163.com>]

check_requires() compares requirement strings that can contain shell
pattern characters such as '[' and ']'. Under /bin/sh, the unquoted
test expressions can emit 'unexpected operator' warnings while parsing
README-backed requirements.

Quote the relevant comparisons and path checks so the helper handles
those patterns without spurious shell warnings.

Validated by rerunning fprobe_syntax_errors.tc and confirming the
previous '/bin/sh: unexpected operator' lines disappear from the
detailed ftracetest log.

Signed-off-by: Cao Ruichuang <create0818@163.com>
---
 tools/testing/selftests/ftrace/test.d/functions | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/tools/testing/selftests/ftrace/test.d/functions b/tools/testing/selftests/ftrace/test.d/functions
index e8e718139..442aa28ff 100644
--- a/tools/testing/selftests/ftrace/test.d/functions
+++ b/tools/testing/selftests/ftrace/test.d/functions
@@ -145,13 +145,13 @@ check_requires() { # Check required files and tracers
 	p=${i%:program}
         r=${i%:README}
         t=${i%:tracer}
-	if [ $p != $i ]; then
-	    if ! which $p ; then
+	if [ "$p" != "$i" ]; then
+	    if ! which "$p" ; then
                 echo "Required program $p is not found."
                 exit_unresolved
 	    fi
-        elif [ $t != $i ]; then
-            if ! grep -wq $t available_tracers ; then
+        elif [ "$t" != "$i" ]; then
+            if ! grep -wq "$t" available_tracers ; then
                 echo "Required tracer $t is not configured."
                 exit_unsupported
             fi
@@ -162,11 +162,11 @@ check_requires() { # Check required files and tracers
 	    else
 		test=$TRACING_DIR
 	    fi
-            if ! grep -Fq "$r" $test/README ; then
+            if ! grep -Fq "$r" "$test"/README ; then
                 echo "Required feature pattern \"$r\" is not in README."
                 exit_unsupported
             fi
-        elif [ ! -e $i ]; then
+        elif [ ! -e "$i" ]; then
             echo "Required feature interface $i doesn't exist."
             exit_unsupported
         fi
@@ -223,4 +223,4 @@ get_mnt_options() {
 	local opts=$(mount | grep -m1 "$mnt_point" | sed -e 's/.*(\(.*\)).*/\1/')
 
 	echo "$opts"
-}
\ No newline at end of file
+}
-- 
2.39.5 (Apple Git-154)