Everywhere: Prefer using {:#x} over 0x{:x}

We have a dedicated format specifier which adds the "0x" prefix, so
let's use that instead of adding it manually.

Kernel/KSyms.cpp

@@ -151,7 +151,7 @@ NEVER_INLINE static void dump_backtrace_impl(FlatPtr base_pointer, bool use_ksym
         if (symbol.symbol->address == g_highest_kernel_symbol_address && offset > 4096)
             dbgln("{:p}", symbol.address);
         else
-            dbgln("{:p}  {} +0x{:x}", symbol.address, symbol.symbol->name, offset);
+            dbgln("{:p}  {} +{:#x}", symbol.address, symbol.symbol->name, offset);
     }
 }