hw/pflash: refactor pflash_data_write()

Move the offset calculation, do it once at the start of the function and
let the 'p' variable point directly to the memory location which should
be updated.  This makes it simpler to update other buffers than
pfl->storage in an upcoming patch.  No functional change.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20240108160900.104835-2-kraxel@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
(cherry picked from commit 3b14a55)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

hw/block/pflash_cfi01.c

@@ -404,33 +404,35 @@ static void pflash_update(PFlashCFI01 *pfl, int offset,
 static inline void pflash_data_write(PFlashCFI01 *pfl, hwaddr offset,
                                      uint32_t value, int width, int be)
 {
-    uint8_t *p = pfl->storage;
+    uint8_t *p;
 
     trace_pflash_data_write(pfl->name, offset, width, value, pfl->counter);
+    p = pfl->storage + offset;
+
     switch (width) {
     case 1:
-        p[offset] = value;
+        p[0] = value;
         break;
     case 2:
         if (be) {
-            p[offset] = value >> 8;
-            p[offset + 1] = value;
+            p[0] = value >> 8;
+            p[1] = value;
         } else {
-            p[offset] = value;
-            p[offset + 1] = value >> 8;
+            p[0] = value;
+            p[1] = value >> 8;
         }
         break;
     case 4:
         if (be) {
-            p[offset] = value >> 24;
-            p[offset + 1] = value >> 16;
-            p[offset + 2] = value >> 8;
-            p[offset + 3] = value;
+            p[0] = value >> 24;
+            p[1] = value >> 16;
+            p[2] = value >> 8;
+            p[3] = value;
         } else {
-            p[offset] = value;
-            p[offset + 1] = value >> 8;
-            p[offset + 2] = value >> 16;
-            p[offset + 3] = value >> 24;
+            p[0] = value;
+            p[1] = value >> 8;
+            p[2] = value >> 16;
+            p[3] = value >> 24;
         }
         break;
     }