devtools: fix result of svg include check

Fix trivial bug. In sh shell, 'foo = 1' is not the same as
'foo=1'. Using 'foo = 1' makes the shell attempt to interpret foo
as a command, rather than a simple variable assignment.

Fixes: dafc04c151 ("devtools: fix return of forbidden addition checks")
Cc: stable@dpdk.org

Signed-off-by: Michael Santana <msantana@redhat.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>
Reviewed-by: David Marchand <david.marchand@redhat.com>

devtools/checkpatches.sh

@@ -73,7 +73,7 @@ check_forbidden_additions() { # <patch>
 		-v RET_ON_FAIL=1 \
 		-v MESSAGE='Using explicit .svg extension instead of .*' \
 		-f $(dirname $(readlink -e $0))/check-forbidden-tokens.awk \
-		"$1" || res = 1
+		"$1" || res=1
 
 	return $res
 }