libcamera: ipa_manager: Simplify addDir() usage

The addDir call only returns an error if it can't open the directory.
Callers only care about the number of modules added, and discard any
error information.

Simplify the return value and calling code by returning an unsigned int
of the number of modules loaded.

Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

src/libcamera/include/ipa_manager.h

@@ -32,7 +32,7 @@ private:
 	IPAManager();
 	~IPAManager();
 
-	int addDir(const char *libDir);
+	unsigned int addDir(const char *libDir);
 };
 
 } /* namespace libcamera */