Compiling current SVN fails with the following error for me:

 cc1: warnings being treated as errors
 buildroot/buildroot/build_powerpc/makedevs/makedevs.c: In function main:
 buildroot/buildroot/build_powerpc/makedevs/makedevs.c:531: error:
 ignoring return value of system, declared with attribute warn_unused_result

This change adds a simple warning if system() fails.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

target/makedevs/makedevs.c

@@ -528,7 +528,8 @@ loop:
 	}
 	fclose(table);
 
-	system("/bin/sync");
+	if (system("/bin/sync"))
+		bb_error_msg("sync failed, continuing anyway");
 
 	return 0;
 }