subr_firmware.c::unloadentry(): remote write-only variable

The function ignores result returned by linker_release_module().
The FW_UNLOAD flag on the file is cleared, so even on error it would
not be tried again.

Sponsored by:	The FreeBSD Foundation
MFC after:	1 week

sys/kern/subr_firmware.c

@@ -412,7 +412,6 @@ static void
 unloadentry(void *unused1, int unused2)
 {
 	struct priv_fw *fp;
-	int err;
 
 	mtx_lock(&firmware_mtx);
 restart:
@@ -434,7 +433,7 @@ unloadentry(void *unused1, int unused2)
 		 * on unload to actually free the entry.
 		 */
 		mtx_unlock(&firmware_mtx);
-		err = linker_release_module(NULL, NULL, fp->file);
+		(void)linker_release_module(NULL, NULL, fp->file);
 		mtx_lock(&firmware_mtx);
 
 		/*