perf tools: Remove excess variable declarations

JIRA: https://issues.redhat.com/browse/RHEL-78200

upstream
========
commit 51f4c00
Author: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Date: Wed Jun 11 15:29:03 2025 +0530

description
===========
I thought array declaration might be done in the same line as assigning the value
to it.

Hence, getting rid of extra steps of reiterating the array name.

    Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com>
    Link: https://lore.kernel.org/r/20250611100256.31089-1-unixbhaskar@gmail.com
    Signed-off-by: Namhyung Kim <namhyung@kernel.org>

Signed-off-by: Anubhav Shelat <ashelat@redhat.com>

Author: AnubhavS1

tools/perf/check-headers.sh

@@ -4,8 +4,7 @@
 YELLOW='\033[0;33m'
 NC='\033[0m' # No Color
 
-declare -a FILES
-FILES=(
+declare -a FILES=(
   "include/uapi/linux/const.h"
   "include/uapi/drm/drm.h"
   "include/uapi/drm/i915_drm.h"
@@ -74,8 +73,7 @@ FILES=(
   "scripts/syscall.tbl"
 )
 
-declare -a SYNC_CHECK_FILES
-SYNC_CHECK_FILES=(
+declare -a SYNC_CHECK_FILES=(
   "arch/x86/include/asm/inat.h"
   "arch/x86/include/asm/insn.h"
   "arch/x86/lib/inat.c"
@@ -87,8 +85,7 @@ SYNC_CHECK_FILES=(
 # tables that then gets included in .c files for things like id->string syscall
 # tables (and the reverse lookup as well: string -> id)
 
-declare -a BEAUTY_FILES
-BEAUTY_FILES=(
+declare -a BEAUTY_FILES=(
   "arch/x86/include/asm/irq_vectors.h"
   "arch/x86/include/uapi/asm/prctl.h"
   "include/linux/socket.h"