[O] Fix shellcheck warnings

neofetch

@@ -2716,7 +2716,7 @@ get_memory() {
             pages_wired="$(vm_stat | awk '/ wired/ { print $4 }')"
             pages_compressed="$(vm_stat | awk '/ occupied/ { printf $5 }')"
             pages_compressed="${pages_compressed:-0}"
-            mem_used="$(((${pages_app} + ${pages_wired//.} + ${pages_compressed//.}) * hw_pagesize / 1024 / 1024))"
+            mem_used="$(((pages_app + ${pages_wired//.} + ${pages_compressed//.}) * hw_pagesize / 1024 / 1024))"
         ;;
 
         "BSD" | "MINIX")