fixed 844ef2a8 from https://gitee.com/maweiye/xts_acts/pulls/6687

fix ActsToolChainTest fail
Signed-off-by: Nmaweiye <maweiye@huawei.com>

commonlibrary/toolchain/libc-test/Test.json

@@ -24,6 +24,7 @@
                 "tar -xf /data/local/tmp/libc-test-lib.tar -C /data/local/tmp/",
                 "chmod a+x -R /data/local/tmp/libc-test-lib",
                 "chmod a+x -R /data/local/tmp/libc-test",
+		"mount -o rw,remount /",
                 "rm -rf /data/local/tmp/libc-test/vsyslog",
                 "rm -rf /data/local/tmp/libc-test/mkstemps",
                 "rm -rf /data/local/tmp/libc-test/mkostemps",
@@ -177,4 +178,4 @@
             "cleanup-apps": true
         }
     ]
-}
\ No newline at end of file
+}