Fix warnings: syntax.c: get_id_list(): Double free: FP.

Problem    : Double free @ 5213.
Diagnostic : False positive.
Rationale  : I haven't been able to find the real reason why this is
             signaled. Nonetheless, I've been able to track down the
             introduction of this warning to commit
             77135447e09903b45d1482da45869946212f7904.
             The change there affecting this function is just a
             transformation maintaining semantics. So, this must be a
             FP, though I can't explain why.
Resolution : Revert changes in mentioned commmit touching this function.

1 files changed, 14 insertions, 15 deletions

diff --git a/src/nvim/syntax.c b/src/nvim/syntax.c
index b7a485598b..3deda0a8c9 100644
--- a/src/nvim/syntax.c
+++ b/src/nvim/syntax.c
@@ -5157,22 +5157,21 @@ get_id_list (
           regmatch.rm_ic = TRUE;
           id = 0;
           for (int i = highlight_ga.ga_len; --i >= 0; ) {
-            if (!vim_regexec(&regmatch, HL_TABLE()[i].sg_name, (colnr_T)0)) {
-              continue;
-            }
-            if (round == 2) {
-              /* Got more items than expected; can happen
-               * when adding items that match:
-               * "contains=a.*b,axb".
-               * Go back to first round */
-              if (count >= total_count) {
-                free(retval);
-                round = 1;
-              } else
-                retval[count] = i + 1;
+            if (vim_regexec(&regmatch, HL_TABLE()[i].sg_name, (colnr_T)0)) {
+              if (round == 2) {
+                /* Got more items than expected; can happen
+                 * when adding items that match:
+                 * "contains=a.*b,axb".
+                 * Go back to first round */
+                if (count >= total_count) {
+                  free(retval);
+                  round = 1;
+                } else
+                  retval[count] = i + 1;
+              }
+              ++count;
+              id = -1;                      /* remember that we found one */
             }
-            ++count;
-            id = -1;                      /* remember that we found one */
           }
           vim_regfree(regmatch.regprog);
         }