build: fixup mksnapshot args on linux (#36531)

.circleci/config/base.yml

@@ -707,7 +707,7 @@ step-mksnapshot-build: &step-mksnapshot-build
         ninja -C out/Default electron:electron_mksnapshot -j $NUMBER_OF_NINJA_PROCESSES
         gn desc out/Default v8:run_mksnapshot_default args > out/Default/mksnapshot_args
         # Remove unused args from mksnapshot_args
-        SEDOPTION=
+        SEDOPTION="-i"
         if [ "`uname`" == "Darwin" ]; then
           SEDOPTION="-i ''"
         fi
@@ -1229,7 +1229,7 @@ commands:
               ninja -C out/Default tools/v8_context_snapshot -j $NUMBER_OF_NINJA_PROCESSES
               gn desc out/Default v8:run_mksnapshot_default args > out/Default/mksnapshot_args
               # Remove unused args from mksnapshot_args
-              SEDOPTION=
+              SEDOPTION="-i"
               if [ "`uname`" == "Darwin" ]; then
                 SEDOPTION="-i ''"
               fi