[PATCH] kernel-parameters.rst: fix document warnings

[Bartlomiej Kubik <kubik.bartlomiej@gmail.com>]

found/fix two warnings in kernel-parameters.rst.

-> WARNING: Missing or malformed SPDX-License-Identifier tag in line 1
-> WARNING: Possible repeated word: 'that'

command: 
./scripts/checkpatch.pl --strict -f Documentation/admin-guide/kernel-parameters.rst


Signed-off-by: Bartlomiej Kubik <kubik.bartlomiej@gmail.com>
---
 Documentation/admin-guide/kernel-parameters.rst | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/Documentation/admin-guide/kernel-parameters.rst b/Documentation/admin-guide/kernel-parameters.rst
index 39d0e7ff0965..445248787e77 100644
--- a/Documentation/admin-guide/kernel-parameters.rst
+++ b/Documentation/admin-guide/kernel-parameters.rst
@@ -1,3 +1,5 @@
+.. SPDX-License-Identifier: GPL-2.0
+
 .. _kernelparameters:
 
 The kernel's command-line parameters
@@ -213,7 +215,7 @@ need or coordination with <Documentation/arch/x86/boot.rst>.
 There are also arch-specific kernel-parameters not documented here.
 
 Note that ALL kernel parameters listed below are CASE SENSITIVE, and that
-a trailing = on the name of any parameter states that that parameter will
+a trailing = on the name of any parameter states that parameter will
 be entered as an environment variable, whereas its absence indicates that
 it will appear as a kernel argument readable via /proc/cmdline by programs
 running once the system is up.
-- 
2.39.5