309b99f3ee
While gcc ignores attempts to disable unknown warnings, clang does not
(`-Wunknown-warning-option`), thus compilation fails due to the recent
addition of `-Wno-sfinae-incomplete`. So only add it conditionally.
Closes: https://gitlab.freedesktop.org/camera/libcamera/-/issues/315
Fixes: aa2a0812e6 ("apps: qcam: Disable -Wsfinae-incomplete")
Signed-off-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>