selftests/kexec: cleanup the kexec selftest

Remove the few bashisms and use the complete option name for clarity.
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

tools/testing/selftests/kexec/test_kexec_load.sh

 #!/bin/sh
-# SPDX-License-Identifier: GPL-2.0+
+# SPDX-License-Identifier: GPL-2.0
 # Loading a kernel image via the kexec_load syscall should fail
-# when the kerne is CONFIG_KEXEC_VERIFY_SIG enabled and the system
+# when the kernel is CONFIG_KEXEC_VERIFY_SIG enabled and the system
 # is booted in secureboot mode.
 
 TEST="$0"
@@ -12,8 +12,8 @@ rc=0
 ksft_skip=4
 
 # kexec requires root privileges
-if [ $UID != 0 ]; then
-	echo "$TEST: must be run as root" >&2
+if [ $(id -ru) -ne 0 ]; then
+	echo "$TEST: requires root privileges" >&2
 	exit $ksft_skip
 fi
 
@@ -33,17 +33,17 @@ secureboot=`hexdump $file | awk '{print substr($4,length($4),1)}'`
 
 # kexec_load should fail in secure boot mode
 KERNEL_IMAGE="/boot/vmlinuz-`uname -r`"
-kexec -l $KERNEL_IMAGE &>> /dev/null
-if [ $? == 0 ]; then
-	kexec -u
-	if [ "$secureboot" == "1" ]; then
+kexec --load $KERNEL_IMAGE > /dev/null 2>&1
+if [ $? -eq 0 ]; then
+	kexec --unload
+	if [ $secureboot -eq 1 ]; then
 		echo "$TEST: kexec_load succeeded [FAIL]"
 		rc=1
 	else
 		echo "$TEST: kexec_load succeeded [PASS]"
 	fi
 else
-	if [ "$secureboot" == "1" ]; then
+	if [ $secureboot -eq 1 ]; then
 		echo "$TEST: kexec_load failed [PASS]"
 	else
 		echo "$TEST: kexec_load failed [FAIL]"