[PATCH i-g-t v2] lib/drmtest: Create proper error report when open driver fails

[Kamil Konieczny <kamil.konieczny@linux.intel.com>]

When first try for opening driver fails then opening function is
searching for next available device. When that also fails
reporting is printing last errno which could mislead developer:

$ build/tests/kms_dp_aux_dev
IGT-Version: 2.3-NO-GIT (x86_64) (Linux: 6.17.0-19-generic x86_64)
Test requirement not met in function drm_open_driver, file ../lib/drmtest.c:754:
Test requirement: !(fd<0)
No known gpu found for chipset flags 0x4294965755 (any)
Last errno: 2, No such file or directory
SKIP (0.006s)

ls /dev/dri
by-path  card1  renderD128

The real problem here is lack of permissions as there was a card
but program could not open it. Break looking for a card as soon
as an error is different from ENOENT. It will create a proper
error report which will print:

Last errno: 13, Permission denied

Cc: Ashutosh Dixit <ashutosh.dixit@intel.com>
Cc: Karthik B S <karthik.b.s@intel.com>
Cc: "Zbigniew Kempczyński" <zbigniew.kempczynski@intel.com>
Signed-off-by: Kamil Konieczny <kamil.konieczny@linux.intel.com>
---
 lib/drmtest.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/lib/drmtest.c b/lib/drmtest.c
index 4a788ea7a..66982f653 100644
--- a/lib/drmtest.c
+++ b/lib/drmtest.c
@@ -443,6 +443,11 @@ static int __search_and_open(const char *base, int offset, unsigned int chipset,
 		fd = __drm_open_device(name, chipset);
 		if (fd != -1)
 			return fd;
+
+		if (errno == ENOENT)
+			continue;
+
+		break;
 	}
 
 	return -1;
-- 
2.53.0