Update post-pve-install.sh

Code refactoring

misc/post-pve-install.sh

@@ -142,9 +142,7 @@ EOF
   esac
 
   microcode=""
-  cpu=$(lscpu | grep -oP 'Vendor ID:\s*\K\S+')
-  if [ "$cpu" == "GenuineIntel" ]; then
-    if lscpu | grep -qP 'Model name:.*N'; then
+  if lscpu | grep -qP 'Vendor ID:.*GenuineIntel' && lscpu | grep -qP 'Model name:.*N'; then
       CHOICE=$(whiptail --title "N-SERIES PROCESSOR DETECTED" --menu "\nTo ensure compatibility with Proxmox VE on systems equipped with N-series processors, it is recommended to install the Proxmox 6.2 kernel.\n\nInstall the Proxmox 6.2 kernel now?" 16 58 2 \
         "yes" " " \
         "no" " " 3>&1 1>&2 2>&3)
@@ -160,7 +158,6 @@ EOF
         ;;
       esac
   fi
-  fi
 
   if [ "$microcode" == "need" ]; then
     CHOICE=$(whiptail --title "INTEL MICROCODE" --menu "\nMicrocode updates can fix hardware bugs, improve performance, and enhance security features of the processor.\n\nInstall the Intel Microcode now?" 16 58 2 \