Werror=sign-compare in qfu-sahara-device.c

On Alpine Linux with musl libc:

In file included from /usr/lib/glib-2.0/include/glibconfig.h:9,
                 from /usr/include/glib-2.0/glib/gtypes.h:32,
                 from /usr/include/glib-2.0/glib/galloca.h:32,
                 from /usr/include/glib-2.0/glib.h:30,
                 from /usr/include/glib-2.0/gobject/gbinding.h:28,
                 from /usr/include/glib-2.0/glib-object.h:23,
                 from qfu-sahara-device.c:30:
qfu-sahara-device.c: In function 'receive_response':
qfu-sahara-device.c:245:20: error: comparison of integer expressions of different signedness: 'gssize' {aka 'int'} and 'guint' {aka 'unsigned int'} [-Werror=sign-compare]
  245 |     g_assert (rlen <= self->priv->buffer->len - 1);
      |                    ^~
/usr/include/glib-2.0/glib/gmacros.h:928:8: note: in definition of macro '_G_BOOLEAN_EXPR'
  928 |    if (expr)                                    \
      |        ^~~~
/usr/include/glib-2.0/glib/gtestutils.h:164:49: note: in expansion of macro 'G_LIKELY'
  164 |                                              if G_LIKELY (expr) ; else \
      |                                                 ^~~~~~~~
qfu-sahara-device.c:245:5: note: in expansion of macro 'g_assert'
  245 |     g_assert (rlen <= self->priv->buffer->len - 1);
      |     ^~~~~~~~
qfu-sahara-device.c: In function 'qfu_sahara_device_firehose_write_block':
qfu-sahara-device.c:656:22: error: comparison of integer expressions of different signedness: 'gssize' {aka 'int'} and 'guint' {aka 'unsigned int'} [-Werror=sign-compare]
  656 |     g_assert (reqlen <= self->priv->transfer_block_size);
      |                      ^~
/usr/include/glib-2.0/glib/gmacros.h:928:8: note: in definition of macro '_G_BOOLEAN_EXPR'
  928 |    if (expr)                                    \
      |        ^~~~
/usr/include/glib-2.0/glib/gtestutils.h:164:49: note: in expansion of macro 'G_LIKELY'
  164 |                                              if G_LIKELY (expr) ; else \
      |                                                 ^~~~~~~~
qfu-sahara-device.c:656:5: note: in expansion of macro 'g_assert'
  656 |     g_assert (reqlen <= self->priv->transfer_block_size);
      |     ^~~~~~~~