General: Swap some math to simpler syntax

neofetch

@@ -1041,7 +1041,7 @@ get_gpu() {
                 fi
 
                 prin "${subtitle}${gpu_num}" "$gpu"
-                gpu_num="$((gpu_num+=1))"
+                ((++gpu_num))
             done
 
             return
@@ -1952,7 +1952,7 @@ get_ascii() {
         line="${line//\$\{??\}}"
         line="${line//\\\\/\\}"
         ((${#line} > ascii_length)) && ascii_length="${#line}"
-        lines="$((lines+=1))"
+        ((++lines))
     done < "$ascii"
 
     # Colors.
@@ -2437,7 +2437,7 @@ prin() {
     printf "%b\n" "${text_padding:+\033[${text_padding}C}${zws}${string}${reset} "
 
     # Calculate info height.
-    info_height="$((info_height+=1))"
+    ((++info_height))
 
     # Log that prin was used.
     prin=1
@@ -2456,7 +2456,7 @@ get_line_break() {
     printf "%s\n" "${zws} "
 
     # Calculate info height.
-    info_height="$((info_height+=1))"
+    ((++info_height))
 
     # Tell info() that we printed manually.
     prin=1