update README.md

as we no longer have the file doc/mini-howto-building-ltp-from-git.txt

Fixes: 20cc687 ("doc: Remove mini-howto-building-ltp-from-git.txt")
Reviewed-by: Petr Vorel <[email protected]>
Signed-off-by: Avinesh Kumar <[email protected]>

Author: Avinesh

README.md

@@ -101,8 +101,7 @@ $ make install
 ```
 
 This will install LTP to `/opt/ltp`.
-* If you have a problem see `doc/mini-howto-building-ltp-from-git.txt`.
-* If you still have a problem see `INSTALL` and `./configure --help`.
+* If you have a problem see `INSTALL` and `./configure --help`.
 * Failing that, ask for help on the mailing list or Github.
 
 Some tests will be disabled if the configure script can not find their build