selftests/run_kselftest.sh: Resolve BASE_DIR with pwd -P

run_kselftest.sh only needs to canonicalize the directory containing the
script itself. Use shell-native path resolution for that by changing into
the directory and calling pwd -P.

This avoids depending on either realpath or readlink -f while still
producing a physical absolute path for BASE_DIR.

Signed-off-by: Ricardo B. Marlière <rbm@suse.com>
Link: https://lore.kernel.org/r/20260320-selftests-fixes-v1-3-79144f76be01@suse.com
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

Author: rbmarliere

tools/testing/selftests/run_kselftest.sh

@@ -4,12 +4,7 @@
 # Run installed kselftest tests.
 #
 
-# Fallback to readlink if realpath is not available
-if which realpath > /dev/null; then
-        BASE_DIR=$(realpath $(dirname $0))
-else
-        BASE_DIR=$(readlink -f $(dirname $0))
-fi
+BASE_DIR=$(cd "$(dirname "$0")" && pwd -P)
 
 cd $BASE_DIR
 TESTS="$BASE_DIR"/kselftest-list.txt