[PATCH iproute2] configure: Fix to minor error caused by 377a09902a57 ("configure: Minor code cleanup")

Commit 377a09902a57 (lines 72 through 76) included a minor code cleanup
to configure, this caused the following error when running ./configure:

grep: grep: No such file or directory
grep: TC_CONFIG_XT: No such file or directory

This patch fixes the error shown above caused by commit 377a09902a57.

Signed-off-by: Firas Khalil Khana <redacted>
---
 configure | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/configure b/configure
index b85eb58b..45fcffb6 100755
--- a/configure
+++ b/configure

@@ -115,7 +115,7 @@ EOF
 check_xt_old_internal_h()
 {
     # bail if previous XT checks has already succeeded.
-    grep -q if grep -q TC_CONFIG_XT $CONFIG && return
+    grep -q TC_CONFIG_XT $CONFIG && return
 
     #check if we need our own internal.h
     cat >$TMPDIR/ipttest.c <<EOF

-- 
2.20.1