libcamera: utils: call secure_getenv() if it exists or workaround with issetugid()

When secure_getenv() is not available, need to have a workaround.

Check if secure_getenv() is present, otherwise call issetugid() on its
place.

Signed-off-by: Giulio Benetti <giulio.benetti@micronovasrl.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
[Kieran: include stdlib.h]
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

src/libcamera/utils.cpp

@@ -7,8 +7,9 @@
 
 #include "utils.h"
 
+#include <stdlib.h>
 #include <string.h>
-#include <sys/auxv.h>
+#include <unistd.h>
 
 /**
  * \file utils.h
@@ -57,10 +58,14 @@ const char *basename(const char *path)
  */
 char *secure_getenv(const char *name)
 {
-	if (getauxval(AT_SECURE))
+#if HAVE_SECURE_GETENV
+	return ::secure_getenv(name);
+#else
+	if (issetugid())
 		return NULL;
 
 	return getenv(name);
+#endif
 }
 
 /**