[PATCH nft v2 4/4] tests: shell: $NFT needs to be invoked unquoted

["Štěpán Němec" <snemec@redhat.com>]

The variable has to undergo word splitting, otherwise the shell tries
to find the variable value as an executable, which breaks in cases that
7c8a44b25c22 ("tests: shell: Allow wrappers to be passed as nft command")
intends to support.

Mention this in the shell tests README.

Fixes: d8ccad2a2b73 ("tests: cover baecd1cf2685 ("segtree: Fix segfault when restoring a huge interval set")")
Signed-off-by: Štěpán Němec <snemec@redhat.com>
---
 tests/shell/README                                       | 3 +++
 tests/shell/testcases/sets/0068interval_stack_overflow_0 | 2 +-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/tests/shell/README b/tests/shell/README
index ea2b0b98f95f..3af17a9e72ca 100644
--- a/tests/shell/README
+++ b/tests/shell/README
@@ -29,4 +29,7 @@ which contains the nft command being tested.
 You can pass an arbitrary $NFT value as well:
  # NFT=/usr/local/sbin/nft ./run-tests.sh
 
+Note that, to support usage such as NFT='valgrind nft', tests must
+invoke $NFT unquoted.
+
 By default, the tests are run with the nft binary at '../../src/nft'
diff --git a/tests/shell/testcases/sets/0068interval_stack_overflow_0 b/tests/shell/testcases/sets/0068interval_stack_overflow_0
index 134282de2826..6620572449c3 100755
--- a/tests/shell/testcases/sets/0068interval_stack_overflow_0
+++ b/tests/shell/testcases/sets/0068interval_stack_overflow_0
@@ -26,4 +26,4 @@ table inet test68_table {
 }
 EOF
 
-( ulimit -s 128 && "$NFT" -f "$ruleset_file" )
+( ulimit -s 128 && $NFT -f "$ruleset_file" )
-- 
2.33.1