Bug 91496

This commit:

pipe-loader: simplify pipe_loader_drm_probe
Do not iterate and (attempt to) open the render device, if we're over
the requested number of devices.

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Reviewed-by: Francisco Jerez <currojerez@riseup.net>

Appears to break the pipe_loader_probe API:

/**
 * Get a list of known devices.
 *
 * \param devs Array that will be filled with pointers to the devices
 *             available in the system.
 * \param ndev Maximum number of devices to return.
 * \return Number of devices available in the system.
 */
int
pipe_loader_probe(struct pipe_loader_device **devs, int ndev);

clover/core/platform.cpp relies on pipe_loader_probe(NULL, 0) to obtain the number of devices available. A fixed upper bound on device count doesn't seem ideal.

It currently appears to work for a single device because pipe_loader_sw_probe returns 1 and this is subsequently used to retrieve the device from pipe_loader_drm_probe.

I think a revert of the above commit is the only way to fulfill this API.