Kernel: Fix SMAP in setkeymap syscall

It looks like setkeymap was missed when
the SMAP functionality was introduced.

Disable SMAP only in the scope where we
actually read the usermode addresses.

Kernel/Process.cpp

@@ -3955,6 +3955,7 @@ int Process::sys$setkeymap(const Syscall::SC_setkeymap_params* params)
     if (!validate_read(altgr_map, 0x80))
         return -EFAULT;
 
+    SmapDisabler disabler;
     KeyboardDevice::the().set_maps(map, shift_map, alt_map, altgr_map);
     return 0;
 }