Add specific exit code for device disconnection

Modify the return logic such that exit code 1 is used when the initial
connection fails, but if a session is established, and then the device
disconnects, exit code 2 is emitted.

Fixes #3083 <https://github.com/Genymobile/scrcpy/issues/3083>
PR #3085 <https://github.com/Genymobile/scrcpy/pull/3085>
Signed-off-by: martin f. krafft <madduck@madduck.net>
Signed-off-by: Romain Vimont <rom@rom1v.com>

app/src/scrcpy.h

@@ -6,7 +6,18 @@
 #include <stdbool.h>
 #include "options.h"
 
-bool
+enum scrcpy_exit_code {
+    // Normal program termination
+    SCRCPY_EXIT_SUCCESS,
+
+    // No connection could be established
+    SCRCPY_EXIT_FAILURE,
+
+    // Device was disconnected while running
+    SCRCPY_EXIT_DISCONNECTED,
+};
+
+enum scrcpy_exit_code
 scrcpy(struct scrcpy_options *options);
 
 #endif