fix:修复拼写错误

Signed-off-by: x_xiny <1301913191@qq.com>
Change-Id: I1cc4897e5d37dd98696221f0cc70220cef45e7d4

testsuites/unittest/common/osTest.cpp

@@ -469,7 +469,7 @@ int RemoveDir(const char *dir)
 
         rmdir(dir); /* now dir is empty */
     } else {
-        perror("unknow file type!");
+        perror("unknown file type!");
     }
     return 0;
 }