exec-all: Fix void pointer arithmetic

Adding an offset to a void pointer works with gcc but is not allowed
by the current C standards. With -pedantic, gcc complains:

exec-all.h:344: error: pointer of type ‘void *’ used in arithmetic

Fix this, and also replace (unsigned long) by (uintptr_t) in the same
statement.

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
diff --git a/exec-all.h b/exec-all.h
index 72ef246..85a37bf 100644
--- a/exec-all.h
+++ b/exec-all.h
@@ -340,8 +340,7 @@
         cpu_abort(env1, "Trying to execute code outside RAM or ROM at 0x" TARGET_FMT_lx "\n", addr);
 #endif
     }
-    p = (void *)(unsigned long)addr
-        + env1->tlb_table[mmu_idx][page_index].addend;
+    p = (void *)((uintptr_t)addr + env1->tlb_table[mmu_idx][page_index].addend);
     return qemu_ram_addr_from_host_nofail(p);
 }
 #endif