selftests/nolibc: Avoid generated files being committed

After running the nolibc tests, the "git status" is not clean because
the generated files are not ignored. Create a `.gitignore` inside the
selftests/nolibc directory to ignore them.

Cc: Ammar Faizi <[email protected]>
Cc: Fernanda Ma'rouf <[email protected]>
Signed-off-by: Fernanda Ma'rouf <[email protected]>
Signed-off-by: Willy Tarreau <[email protected]>
Signed-off-by: Paul E. McKenney <[email protected]>

Author: Fernanda Ma'rouf

tools/testing/selftests/nolibc/.gitignore

@@ -0,0 +1,4 @@
+/initramfs/
+/nolibc-test
+/run.out
+/sysroot/