gendispatch: Don't output spaces on empty line

In our generator for some code we put empty lines in the output
to separate blocks of code. However, in some cases we put couple
of spaces on the empty line too. It's not bug, it just isn't
nice.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>

src/rpc/gendispatch.pl

@@ -677,7 +677,7 @@ elsif ($mode eq "server") {
                     push(@prepare_ret_list,
                          "if (VIR_ALLOC($2_p) < 0)\n" .
                          "        goto cleanup;\n" .
-                         "    \n" .
+                         "\n" .
                          "    if (VIR_STRDUP(*$2_p, $2) < 0)\n".
                          "        goto cleanup;\n");